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<strong>THE</strong> <strong>JOURNAL</strong> <strong>OF</strong><br />
ADHESIVE<br />
DENTISTRY<br />
VOLUME 9 • SUPPLEMENT 2<br />
2007
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There are many adhesives available. Some bond a little better, others are<br />
easy to use and again others are more forgiving. The new total-etch adhesive<br />
XP BOND unites all these attributes in one single product.<br />
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Who needs the rest, when you can have it all inclusive
Guest Editorial<br />
Satellite Symposium on Dental Adhesives,<br />
Dublin, September 13th, 2006<br />
Dear ColIeagues,<br />
I clearly remember the moment: During a German conservative<br />
dentistry congress focusing on adhesive vs conventional<br />
techniques in 2004, one of my colleagues said: “I do<br />
not think that ‘adhesive dentistry’ really exists. Okay, there<br />
is even a journal named like that. I admit that there may be<br />
something like an adhesive technique in dentistry, but I don’t<br />
think this is really a discipline.”<br />
Now, two years later with the previously mentioned journal<br />
having received an impact factor of more than 2.2, the<br />
world can see how important this discipline has become in<br />
the dental literature.<br />
For decades, <strong>Dentsply</strong> has been one of the leading companies<br />
dealing with adhesion. This supplement is the scientific<br />
result of a satellite symposium held in Dublin on September<br />
13th, 2006, prior to the annual IADR/CED/PEF<br />
meeting just around the corner from famous Trinity College.<br />
Experts from all over the world (USA, Germany, Belgium,<br />
Spain, Italy) met to exchange experiences with established<br />
adhesive materials and the most recent <strong>Dentsply</strong> development,<br />
XP-Bond. We learned that <strong>Dentsply</strong>’s Sevriton actually<br />
was the first adhesive approach, dated years before<br />
Buonocore’s fundamental publication. We heard that fatigue<br />
measurement is one major tool in preclinical testing<br />
and that differences in performance during in vitro testing<br />
blur between etch-and-rinse and self-etching adhesives; it is<br />
becoming more important to look at the individual product.<br />
However, clinical trials are still the ultimate instrument to investigate<br />
dental biomaterials, such as bonded resin composites<br />
or ceramic inlays.<br />
It is an honor for me to welcome you to this supplement<br />
of the Journal of Adhesive Dentistry, 2007. Enjoy reading!<br />
Sincerely,<br />
Roland Frankenberger<br />
Vol 9, Supplement 2, 2007 223
Sarrett<br />
260 The Journal of Adhesive Dentistry
<strong>THE</strong> <strong>JOURNAL</strong> <strong>OF</strong><br />
ADHESIVE<br />
DENTISTRY<br />
Contents Volume 9 • Supplement 2, 2007<br />
Editorial<br />
Reviews<br />
223<br />
227<br />
231<br />
241<br />
245<br />
249<br />
255<br />
261<br />
265<br />
269<br />
275<br />
279<br />
Satellite Symposium on Dental Adhesives, Dublin, September 13th, 2006<br />
Roland Frankenberger<br />
Dental Adhesives …. How it All Started and Later Evolved<br />
Karl-Johan M. Söderholm<br />
Effectiveness of All-in-one Adhesive Systems Tested by Thermocycling Following<br />
Short and Long-term Water Storage<br />
Uwe Blunck/Paul Zaslansky<br />
Clinical Bonding of a Single-step Self-etching Adhesive in Noncarious Cervical<br />
Lesions<br />
Jan WV van Dijken/Karin Sunnegårdh-Grönberg/Ebba Sörensson<br />
Shear Bond Strength and Physicochemical Interactions of XP BOND<br />
Mark A. Latta<br />
Microshear Fatigue Testing of Tooth/Adhesive Interfaces<br />
Marc Braem<br />
Microleakage of Class V Composite Restorations Placed with Etch-and-Rinse<br />
and Self-etching Adhesives Before and After Thermocycling<br />
Juan Ignacio Rosales-Leal<br />
Microleakage of XP BOND in Class II Cavities After Artificial Aging<br />
Jürgen Manhart/Cordula Trumm<br />
Six-month Clinical Evaluation of XP BOND in Noncarious Cervical Lesions<br />
Uwe Blunck/Katharina Knitter/Klaus-Roland Jahn<br />
Adhesive Luting Revisited: Influence of Adhesive, Temporary Cement, Cavity<br />
Cleaning, and Curing Mode on Internal Dentin Bond Strength<br />
Roland Frankenberger/Ulrich Lohbauer/Michael Taschner/Anselm Petschelt/<br />
Sergej A. Nikolaenko<br />
XP BOND in Self-curing Mode used for Luting Porcelain Restorations.<br />
Part A: Microtensile Test<br />
Ornella Raffaelli/Maria Crysanti Cagidiaco/Cecilia Goracci/Marco Ferrari<br />
XP BOND in Self-curing mode used for Luting Porcelain Restorations.<br />
Part B: Placement and 6-month Report<br />
Marco Ferrari/Ornella Raffaelli/Maria Crysanti Cagidiaco/Simone Grandini<br />
Vol 9, Supplement 2, 2007 225
<strong>THE</strong> <strong>JOURNAL</strong> <strong>OF</strong><br />
ADHESIVE<br />
DENTISTRY<br />
Editors-in-Chief<br />
Prof. Dr.<br />
Jean-François Roulet<br />
Escher Str. 9<br />
FL 9494 Schaan, Liechtenstein<br />
Tel: ++423 232 1632<br />
Fax: ++423 239 4632<br />
Mobile phone +41 79 311 4673<br />
E-mail: jfroulet@aol.com<br />
Submit the manuscripts and<br />
illustrations preferably through:<br />
www. manuscriptmanager.com/jadd<br />
Or mail to:<br />
Quintessenz Verlags-GmbH,<br />
Juliane Richter<br />
The Journal of Adhesive Dentistry,<br />
Ifenpfad 2-4, D-12107 Berlin, Germany<br />
Editorial Board<br />
Antonson, S. (USA)<br />
Assmussen, E. (Denmark)<br />
Attal, J.-P. (France)<br />
Bayne, S. (USA)<br />
Blatz, M. (USA)<br />
Blunck, U. (Germany)<br />
Bouillaguet S. (Switzerland)<br />
Brabant, A. (Belgium)<br />
Burrow, M. (Australia)<br />
Burtscher, P. (Liechtenstein)<br />
Carvalho, R. (Brazil)<br />
Cognard, J. (Switzerland)<br />
Creugers, N. (Netherlands)<br />
Davidson, C.L. (Netherlands)<br />
Dejou, J. (France)<br />
Dietschi, D. (Switzerland)<br />
Eliades, G. (Greece)<br />
Erickson, R.L. (USA)<br />
Ferracane, J. (USA)<br />
Ferrari, M. (Italy)<br />
Finger, W. (Germany)<br />
Frankenberger, R. (Germany)<br />
Fuzzi, M. (Italy)<br />
Glantz, P.-O. (Sweden)<br />
Heintze, S. (Liechtenstein)<br />
Hickel, R. (Germany)<br />
Jacobsen, T. (Sweden)<br />
Jahn, K.-R. (Germany)<br />
Janda, R. (Germany)<br />
Kern, M. (Germany)<br />
Kreulen, C. (Netherlands)<br />
Kugel, G. (USA)<br />
Kulmer, S. (Austria)<br />
Kunzelmann, K.-H. (Germany)<br />
Lambrechts, P. (Belgium)<br />
Liebenberg, W. H. (Canada)<br />
Lynch E. (Irland)<br />
Macorra de la, J.C. (Spain)<br />
Matsumura, H. (Japan)<br />
Mehl, A. (Germany)<br />
Momoi, Y. (Japan)<br />
Munksgaard, Ch. (Denmark)<br />
Nakabayashi, N. (Japan)<br />
Navarro, F. (Brazil)<br />
Nikaido, T. (Japan)<br />
Noack, M.J. (Germany)<br />
Özcan, M. (Netherlands)<br />
Pashley, D. H. (USA)<br />
Paul, S. J. (Switzerland)<br />
Perdigao, J. (USA)<br />
Peutzfeld, A. (Denmark)<br />
Powers, J. M. (USA)<br />
Prati, C. (Italy)<br />
Qvist, V. (Denmark)<br />
Ruse, D. (Canada)<br />
Salz, U. (Liechtenstein)<br />
Samama, Y. (France)<br />
Sano, H. (Japan)<br />
Schultz, J. (France)<br />
Senda A. (Japan)<br />
Simonsen, R.J. (USA)<br />
Söderholm, K.-J. (USA)<br />
Spreafico, R. (Italy)<br />
Städtler, P. (Austria)<br />
Suzuki, S. (USA)<br />
Tay, F. (China)<br />
Thompson, V. P. (USA)<br />
Toreskog, S. (Sweden)<br />
Triolo, P. T. (USA)<br />
Tyas, M. J. (Australia)<br />
Vallittu, P. (Finland)<br />
Van Noort, R. (United Kingdom)<br />
Vargas, M. (USA)<br />
Watson, T. (United Kingdom)<br />
Wilson, N. H. F. (United Kingdom)<br />
Statistical Consultant<br />
Fischer T. H. (Germany)<br />
Hopfenmüller, W. (Germany)<br />
ISSN 1461-5185<br />
Prof. Bart Van Meerbeek<br />
Catholic University of Leuven<br />
Department of Conservative Dentistry<br />
Kapucijnenvoer 7<br />
B-3000 Leuven, Belgium<br />
Tel: ++32 16 337587<br />
Fax: ++32 16 332752<br />
E-mail: Bart.Vanmeerbeek@<br />
med.kuleuven.ac.be<br />
The Journal of Adhesive Dentistry publishes scientifically sound articles of interest<br />
to practitioners and researchers in the field of adhesion to hard and soft dental<br />
tissues. Included are clinical and basic science research reports based on original<br />
research in adhesive dentistry and related subjects, review articles on topics<br />
related to adhesive dentistry, as well as invited focus articles with commentaries.<br />
The Journal of Adhesive Dentistry is Indexed in Science Citation Index Expanded,<br />
ISI Alerting Services, and Current Contents/Clinical Medicine.<br />
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Dental Adhesives …. How it All Started and Later Evolved<br />
Karl-Johan M. Söderholm a<br />
Abstract: This article describes how dental adhesives evolved from the cements developed by the Mayan Indians into<br />
today’s modern dental adhesives. Particular attention is paid to Oskar Hagger, a chemist who worked for DeTrey/Amalgamated<br />
Dental Company, and already in 1949 developed an adhesive product called Sevriton Cavity Seal. That adhesive<br />
was acidic and interacted with the tooth surface on a molecular level. His ground-breaking concept makes him the<br />
true “Father of Modern Dental Adhesives.” Hagger’s concept was soon adopted by other investigators, and different generations<br />
of dental adhesives evolved thereafter. Today, after many years of accepting that the key to the success of dental<br />
adhesives is the micromechanical retention resulting from acid etching of dentin and enamel, we still return to Dr.<br />
Hagger’s original concept that bonding can be achieved via molecular interactions between adhesives and tooth surfaces.<br />
That concept is obvious in the development of newer generations of dentin adhesives. These adhesives, like Sevriton<br />
Cavity Seal, rely on acidic monomers capable of etching and interacting on a molecular level with tooth surfaces in<br />
order to form physical/chemical bonds between the restoration and the tooth. Whether Hagger’s concept will become<br />
the norm in the future is still an open question, but one thing is certain: Hagger’s idea is still very much alive.<br />
Keywords: review, generations, clinical evaluations.<br />
J Adhes Dent 2007; 9: 227-230. Submitted for publication: 15.12.06; accepted for publication: 4.1.07.<br />
a Professor, Department of Dental Biomaterials, College of Dentistry, University<br />
of Florida, Gainesville, FL, USA.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Prof. Karl-Johan M. Söderholm, Department of Dental Biomaterials,<br />
College of Dentistry, College of Dentistry, 1600 SW Archer Road,<br />
Gainesville, FL 32610-0446, USA. Tel: +1-352-392-0575, Fax: +1-352-392-7808.<br />
e-mail: ksoderholm@dental.ufl.edu<br />
In 1955, Buonocore published a paper entitled “A simple<br />
method of increasing the adhesion of acrylic filling materials<br />
to enamel surfaces”. 15 That paper is often regarded as<br />
the foundation of adhesive dentistry, and today that paper<br />
is the 17th most cited paper published in the Journal of Dental<br />
Research since March of 1919.<br />
Buonocore’s paper 15 clearly outlined different approaches<br />
to obtain bonding between filling materials and tooth<br />
structure. These approaches included: (a) the development<br />
of new materials which have adhesive properties, (b) modification<br />
of present materials to make them adhesive, (c) the<br />
use of coatings as adhesive interface materials between filling<br />
and tooth, and (d) the alteration of the tooth surface by<br />
chemical treatment to produce a new surface to which present<br />
materials might adhere.<br />
In the 1955 paper, Buonocore focused on the (d) alternative<br />
by targeting enamel bonding. He believed that treatment<br />
of intact enamel surfaces would have only limited application<br />
to the broader problems of restorative dentistry. He<br />
focused on enamel etching because he had found that phosphoric<br />
acid or preparations containing phosphoric acid had<br />
been used to treat metal surfaces in order to obtain better<br />
adhesion of paint and different resin coatings.<br />
Obviously, Buonocore used knowledge from other disciplines<br />
and transferred that knowledge to dentistry. What<br />
Buonocore did not seem to consider was that the Mayan Indians<br />
in pre-Columbian times had used acidic cements to attach<br />
their semi-precious stone inlays. 20 He also forgot to<br />
consider that several acidic cements had been used by dentists<br />
more than a hundred years before he invented acid<br />
etching, 27 and that a common zinc phosphate cement was<br />
a mixture of zinc oxide and phosphoric acid. 37 It was well<br />
known that during setting, these cements remained<br />
acidic. 40 What Buonocore forgot was that these cements<br />
were also able to etch tooth surfaces and increase the surface<br />
roughness. During setting, formed setting compounds<br />
grew into the surface roughnesses created by the acidic cement.<br />
Because of mechanical interlocking between tooth,<br />
cement, and crown, retention of the cemented restoration<br />
could be achieved. Considering that the Maya were the first<br />
to use acidic cements, a legitimate question is whether<br />
Buonocore really was the one who invented acid etching or<br />
if that honor shouldn’t go to the Maya. Buonocore’s true contribution<br />
was that he opened our eyes to make us aware of<br />
Vol 9, Supplement 2, 2007 227
Söderholm<br />
Fig 1 Sevriton and Severiton Cavity seal were products developed<br />
by the DeTrey/Amalgamated Dental Company. Sevriton Cavity<br />
Seal was the first product claimed to be able to bond to tooth<br />
tissues. 29 This product was developed by the Swiss chemist,<br />
Oskar Hagger.<br />
the fact that microscopic porosities enhanced the retention<br />
of dental materials. What he did not communicate clearly,<br />
though, was that by replacing a brittle cement layer with a<br />
ductile material, the bonding ability could be substantially<br />
enhanced. The latter fact was probably the reason why the<br />
acid etching technique resulted in a major breakthrough in<br />
dentistry when compared to previous approaches to bonding<br />
to teeth.<br />
However, when it comes to a ductile interface, Buonocore<br />
was not the first to use a ductile resin layer at the tooth surface<br />
in order to enhance retention. The first one who came<br />
up with that idea was a Swiss chemist, Oskar Hagger. Hagger<br />
worked for DeTrey/Amalgamated Dental Company, and<br />
had already in 1949 developed an adhesive product called<br />
Sevriton Cavity Seal 33 (Fig 1). This product consisted of glycerolphosphoric<br />
acid dimethacrylate and was intended for<br />
use as an adhesive for the chemically cured resin Sevriton.<br />
Sevriton Cavity Seal was indeed a revolutionary product, because<br />
it was the first product that claimed to be able to<br />
chemically bond to tooth structure. In an article published by<br />
Kramer and McLean in 1952, 29 these two investigators<br />
claimed that the glycerolphosphoric acid dimethacrylate of<br />
the Sevriton Cavity Seal increased the adhesion to dentin by<br />
penetrating the surface. Today we call the resin-penetrated<br />
zone the hybrid zone. This is also remarkable, because we<br />
often assume that hybridization is a more recent discovery<br />
than it obviously is.<br />
The year after Buonocore published his classic paper, he<br />
also published a paper with Brudevold and Wileman, 13 in<br />
which they evaluated Sevriton Cavity Seal and Sevriton. In<br />
that paper they claimed that the glycerolphosphoric acid<br />
dimethacrylate did not bond as well to enamel as a self-curing<br />
resin placed in intimate contact with a phosphoricacid–etched<br />
enamel surface did. However, when placed in<br />
contact with dentin, the glycerolphosphoric acid dimethacrylate<br />
provided some dentin bond enhancement.<br />
Considering Hagger’s fundamental work, there is no<br />
doubt that modern dental adhesive technology had its root<br />
in the late 1940s, when Hagger initiated the use of acidic<br />
monomers to achieve bonding to both enamel and dentin.<br />
What Buonocore really showed was that it was easier to<br />
achieve bonding to enamel than to dentin, something we all<br />
agree upon today.<br />
Even though Buonocore had proved that enamel bonding<br />
worked in 1955, 15 it would take until the late 1970s before<br />
enamel bonding became generally accepted. The turning<br />
point occurred when 3M sponsored the International Symposium<br />
on Enamel Etching in December of 1974. 38 During<br />
that symposium, researchers and clinicians with experience<br />
of enamel bonding presented their findings, and 3M published<br />
and distributed that information to academic institutions<br />
and opinion leaders.<br />
The idea to develop a resin system capable of bonding to<br />
dentin did not die with Hagger. Instead, Bowen, after his invention<br />
of modern composites, focused on dentin adhesives<br />
during the 1960s. During that decade, he formed work<br />
groups that outlined strategies for developing new dental adhesives.<br />
7-11 Guiding principles during these discussions<br />
were: (a) dentin is a vital tissue and should not be exposed<br />
to strong acids, (b) the presence of water should be minimized,<br />
because water would shield bond sites of adhesive<br />
molecules, (c) the adhesive molecules should be at least bifunctional<br />
so one end could bond to tooth surface and the<br />
other to the resin of the composite.<br />
As a result of Bowen’s research, NPG-GMA (N-phenylglycine<br />
and glycidyl methacrylate) was introduced in 1965 as<br />
a potential dentin adhesive. The shear bond strength of this<br />
first generation adhesive was 1 to 3 MPa, and it soon became<br />
obvious that these products did not work clinically.<br />
During the late 1970s, new dentin adhesives were developed.<br />
Most of these products contained of bis-GMA/HEMA<br />
resins mixed with halophosphorous esters. The bonding<br />
mechanism of these adhesives was believed to be due to<br />
ionic bond formation between halophosphorous groups and<br />
calcium ions of the tooth surface. Even though these second<br />
generation products were significant improvements compared<br />
to the first generation products, they still did not result<br />
in clinical success.<br />
A major breakthrough occurred in 1979, when Fusayama<br />
and his coworkers presented their findings, claiming they<br />
could bond to acid-etched dentin without any significant<br />
problems with pulp reactions. 22 The paper was met with ample<br />
skepticism by authorities in pulp biology who argued<br />
that the acidity would cause pulp inflammations and even<br />
pulp necrosis. Fusayama, on the other hand, argued that his<br />
findings were just supporting Brännström and Nyborg’s<br />
claim that bacteria rather than acid was the key concern<br />
when it came to causing pulp damage. 12<br />
Another important paper from Japan came in 1982,<br />
when Nakabayashi and coworkers published their paper<br />
“The promotion of adhesion by the infiltration of monomers<br />
into tooth substrates”. This paper presented the hybrid-layer<br />
formation theory. 35<br />
The findings from Fusayama’s and Nakabayashi’s groups<br />
228 The Journal of Adhesive Dentistry
Söderholm<br />
resulted in a new generation of adhesives, the so-called 3rd<br />
generation adhesives. Manufacturers of adhesives were still<br />
somewhat reluctant to suggest an aggressive acid etching of<br />
the dentin. Instead, they tried to remove or modify the smear<br />
layer with a conditioner (often a weaker acidic solution) that<br />
was rinsed away before a hydrophilic primer was placed.<br />
These primers often consisted of 4-META and BPDM, and after<br />
primer application, an unfilled resin was placed. Other<br />
primers contained PENTA, HEMA and ethanol. One product<br />
used EDTA instead of acid to remove the smear layer and expose<br />
the collagen, and treated the exposed collagen fibers<br />
first with an aldehyde and then HEMA. 34 With that treatment,<br />
it was believed that the aldehyde would chemically<br />
bond to the collagen fiber and that the HEMA would then<br />
bond to the attached aldehyde molecules via a condensation<br />
reaction. The methacrylate groups of the HEMA molecule<br />
would then react with the composite.<br />
Interesting to mention is that Bowen and Cobb published<br />
a paper in 1983 entitled “A method for bonding to dentin<br />
and enamel”, 6 in which they claimed they could achieve an<br />
in vitro tensile bond strength corresponding to one ton per<br />
square inch. Translated into metric units, that would be 15.5<br />
MPa. The bonding procedure was rather complex, but in that<br />
article, Bowen regarded this approach as a major breakthrough<br />
despite its complexity.<br />
Even though the 3rd generation adhesives were improvements,<br />
they did not result in long-term success. In<br />
1985, Hansen and Asmussen correlated gap sizes around<br />
standardized cavities with the shear bond strength and<br />
found that gap-free restorations would be possible at shear<br />
bond strength values of around 23 MPa. 25 The best adhesives<br />
then had shear strength values of 18 MPa.<br />
Toward the end of the 1980s, some interesting research<br />
was published. The first paper came in 1985, when Bowen<br />
presented an abstract at an IADR meeting that contained information<br />
on the NTG-GMA he had been so enthusiastic<br />
about in his and Cobb’s 1983 publication. 5 In the 1985 presentation,<br />
he revealed that the adhesive he had used in<br />
1983 contained an impurity. That impurity was nitric acid,<br />
and after purifying, the bond strength declined substantially.<br />
What he inadvertantly showed was how important it was<br />
to etch the dentin surface.<br />
Another important finding came in 1989, when Chigira et<br />
al treated an EDTA-conditioned dentin surface with aldehyde<br />
plus HEMA or HEMA only and found no difference in<br />
bond strength. 17 What they showed with that study was that<br />
collagen exposure and resin infiltration was the key behind<br />
dentin bonding, thereby supporting Nakabayashi’s hybridization<br />
theory.<br />
Some of the most important information came in 1994,<br />
when Van Herle’s group at the Catholic University of Leuven<br />
showed in a clinical study that the success rate of Scotchbond<br />
2, a third generation dentin adhesive, exceeded 95% after 3<br />
years. 43 Because of poor storage stability, Scotchbond 2 disappeared<br />
from the market almost immediately after it had<br />
been accepted and was replaced by Scotchbond MP, a 4th<br />
generation adhesive. At that time, it had started to become<br />
clear that by using more aggressive dentin treatments, the<br />
bond strength improved and exceeded the levels predicted by<br />
Hanssen and Asmusen for gap-free restorations. 25<br />
Even though Fusayama and later on Nakabayashi had<br />
done extensive research on dentin etching and dentin bonding<br />
during the 1980s, it was during the early 1990s that<br />
dentin etching and dentin bonding first became widely accepted.<br />
The acceptance coincided with a symposium sponsored<br />
by 3M and later on published in Operative Dentistry. 4<br />
Another important discovery was when Kanka 28 and Gwinnett<br />
24 in two independent papers showed that bonding to<br />
dentin could be enhanced by using so-called moist bonding.<br />
Knowledge transfer is rarely an easy task, and when it<br />
came to introducing the 4th generation adhesives to the<br />
dental profession, it was soon clear that dentists did not really<br />
know how to do dentin bonding. Sometimes different<br />
components were used in the wrong order, and when it came<br />
to moist dentin, the definition differed quite widely. Because<br />
of these factors, there was a need for products that were<br />
easier to use, a demand to which the manufacturers soon<br />
responded.<br />
In an attempt to simplify dentin bonding, the primer and<br />
adhesive resin were combined. Unfortunately, the general<br />
perception among clinicians was often that by using a 5th<br />
rather than a 4th generation adhesive, the time needed for<br />
the bonding procedure could be decreased. In reality,<br />
though, such a belief was incorrect, because these systems<br />
required more time for the primer to diffuse into the collagen<br />
structure. Clinical studies that came out comparing the 4th<br />
and the 5th generation adhesives often suggested that the<br />
4th generation adhesives performed somewhat better than<br />
the 5th generation adhesives. 1,14,31,42 Whether that difference<br />
was due to 5th generation adhesives curing too quickly<br />
has not been proven. However, in vitro results of different<br />
generation adhesives can be similar, independent of generation.<br />
19<br />
Simultaneously with the introduction of the 5th generation<br />
adhesives, new adhesives consisting of an acidic primer<br />
and an adhesive were also introduced. These systems often<br />
came from Japanese manufacturers of dental adhesives,<br />
and did not include the etching gel. Because of the generation<br />
terminology, these systems are referred to as the 6th<br />
generation of adhesives.<br />
In 1998, a new adhesive named Prompt-L-Pop was introduced,<br />
consisting of a delivery system that mixed the primer<br />
and the adhesive before it was applied. The popularity of this<br />
system grew quickly and it soon became quite clear that the<br />
market wanted a system that was self-etching and available<br />
in one single container. During the past few years, the trend<br />
has been to move the adhesive one step further by combining<br />
the acidic primer with the adhesive resin in an attempt<br />
to develop an all-in-one system, often marketed as 7th generation<br />
adhesives.<br />
The interest in the 7th generation products has been<br />
quite significant, despite the fact that these systems often<br />
perform less satisfactorily than many of the previous generation<br />
adhesives. 39 However, it is important to emphasize<br />
that all products, including the 7th generation adhesives,<br />
have learning curves. The knowledge generated during<br />
these trial periods is used to develop and improve products<br />
that do not perform as well as originally believed. Unfortunately,<br />
these development periods can be quite frustrating<br />
for the clinicians when faced with patients who have re-<br />
Vol 9, Supplement 2, 2007 229
Söderholm<br />
ceived a restoration that later fails. Today, most research indicates<br />
that the 4th generation adhesives still serve as the<br />
gold standard, but because of the interest dentists show in<br />
the 7th generation adhesives, it seems clear that dentists<br />
want simple-to-use adhesives. Because of that wish, they are<br />
willing to explore adhesives that are easier to use, despite<br />
the risk that they may have more failures with such products.<br />
Thanks to what has been learned during that cycle of the<br />
evolution process, these easier-to-use products have<br />
evolved during the past few years, and today it seems that<br />
the clinical success rate of 7th generation adhesives is approaching<br />
that of the 4th generation adhesives. 2,3,16,18,21,23,<br />
26,30,32,36,41,44<br />
By looking back at adhesives, we must admit that<br />
progress has been made since Hagger’s idea that resins<br />
could be bonded to tooth surfaces. Nevertheless, we should<br />
also remember that in 1949, when Hagger came up with his<br />
revolutionary idea to use glycerolphosphoric acid dimethacrylate<br />
in Sevriton Cavity Seal, he had in fact invented a selfetching<br />
adhesive. Based on the definitions, we can classify<br />
Sevriton Cavity Seal as a 7th generation adhesive. Perhaps<br />
improvements of dental materials don’t occur as fast as<br />
many of us believe.<br />
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12. Brännström M, Nyborg H. The presence of bacteria in cavities filled with silicate<br />
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13. Brudevold F, Buonocore M, Wileman W. A report on a resin composition capable<br />
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14. Brunton PA, Cowan AJ, Wilson MA, Wilson NH. A three-year evaluation of<br />
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15. Buonocore M. A simple method of increasing the adhesion of acrylic filling<br />
materials to enamel surfaces. J Dent Res 1955;34:849-853.<br />
16. Burrow MF, Tyas MJ. Two-year clinical evaluation of One-Up Bond F in noncarious<br />
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17. Chigira H, Manabe A, Itoh K, Wakumoto S, Hayakawa T. Efficacy of glyceryl<br />
methacrylate as a dentin primer. Dent Mater J 1989;8:194-199.<br />
18. Dalton Bittencourt D, Ezecelevski IG, Reis A, Van Dijken JW, Loguercio AD. An<br />
18-months' evaluation of self-etch and etch & rinse adhesive in non-carious<br />
cervical lesions. Oper Dent 2005;30:275-281.<br />
19. Dunn WJ, Söderholm KJ. Comparison of shear and flexural bond strength<br />
tests versus failure modes of dentin bonding systems. Am J Dent 2001;<br />
14:297-303.<br />
20. Fastlicht S. Tooth Mutilations and Dentistry in Pre-Columbian Mexico. Chicago:<br />
Quintessence 1976.<br />
21. Federlin M, Thonemann B, Schmalz G, Urlinger T. Clinical evaluation of different<br />
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1998;2:58-66.<br />
22. Fusayama T, Nakamura M, Kurosaki N, Iwaku M. Non-pressure adhesion of<br />
a new adhesive restorative resin. J Dent Res 1979;58:1364-1370.<br />
23. Gallo JR, Burgess JO, Ripps AH, Walker RS, Ireland EJ, Mercante DE, Davidson<br />
JM. Three-year clinical evaluation of a compomer and a resin composite<br />
as Class V filling materials. Oper Dent 2005;30:275-281.<br />
24. Gwinnett AJ. Moist versus dry dentin: its effect on shear bond strength. Am<br />
J Dent 1992;5:127-129.<br />
25. Hansen EK, Asmussen E. A comparative study of dentin adhesives. Scand J<br />
Dent Res 1985;93:280-287.<br />
26. Helbig EB, Klimm HW, Schreger IE, Haufe E, Natusch I. Controlled clinical<br />
study of the anterior composite-adhesive system Point 4/OptiBond Solo Plus.<br />
Schweiz Monatsschr Zahnmed 2002;112:1230-1235.<br />
27. Hoffmann-Axthelm W. History of Dentistry. Chicago: Quintessence, 1976:<br />
293-295.<br />
28. Kanca J 3rd: Resin bonding to wet substrate. 1. Bonding to dentin. Quintessence<br />
Int 1992; 23:39-41.<br />
29. Kramer IRH, McLean JW. The response of the human pulp to self-polymerising<br />
acrylic. Br Dent J 1952;93:150-153.<br />
30. Kubo S, Kawasaki K, Yokota H, Hayashi Y. Five-year clinical evaluation of two<br />
adhesive systems in non-carious cervical lesions. J Dent 2006;34:97-105.<br />
31. Mandras RS, Thurmond JW, Latta MA, Matranga LF, Kildee JM, Barkmeier<br />
WW. Three-year clinical evaluation of the Clearfil Liner Bond system. Oper<br />
Dent 1997;22:266-270.<br />
32. Matis BA, Cochran MJ, Carlson TJ, Guba C, Eckert GJ. A three-year clinical<br />
evaluation of two dentin bonding agents. J Am Dent Assoc 2004;135:451-<br />
457.<br />
33. McLean JW. Historical Overview: The pioneers of Enamel and dentin bonding.<br />
In: Roulet J-F, Degrange M (eds). Adhesion – The silent revolution in dentistry.<br />
Chicago: Quintessence, 2000;13-17.<br />
34. Munksgaard EC, Assmussen E. Bond strength between dentin and restorative<br />
resins mediated by a mixture of HEMA and glutaraldehyde. J Dent Res<br />
1984;63:1087-1089.<br />
35. Nakabayashi N, Kojima K, Masuhara E. The promotion of adhesion by the infiltration<br />
of monomers into tooth substrates. J Biomed Mater Res 1982 ;<br />
16:265-273.<br />
36. Perdigao J, Carmo AR, Geraldeli S. Eighteen-month clinical evaluation of two<br />
dentin adhesives applied on dry vs moist dentin. J Adhes Dent 2005;7:253-<br />
258.<br />
37. Servais Ge, Cartz L. Structure of zinc phosphate dental cement. J Dent Res<br />
1971;50:613-620.<br />
38. Silverstone LE, Dogon II. Proceedings of an international symposium on. The<br />
Acid Etch Technique. St. Paul: North Central, 1975.<br />
39. Söderholm KJ, Guelmann M, Bimstein E. Shear bond strength of one 4th and<br />
two 7th generation bonding agents when used by operators with different<br />
bonding experience. J Adhes Dent 2005;7:57-64.<br />
40. Stanley HR, Going RE, Chauncey HH. Human pulp response to acid pretreatment<br />
of dentin and to composite restoration. J Am Dent Assoc 1975;91:817-<br />
825.<br />
41. Türkün SL. Clinical evaluation of a self-etching and a one-bottle adhesive system<br />
at two years. J Dent 2003;31:527-534.<br />
42. van Dijken JW. Clinical evaluation of three adhesive systems in class V noncarious<br />
lesions. Dent Mater 2000;16:285-291.<br />
43. Van Meerbeek B, Braem M, Lambrechts P, Vanherle G. Evaluation of two<br />
dentin adhesives in cervical lesions. J Prosthet Dent 1994;72:672-673.<br />
44. Van Meerbeek B, Kanumilli PV, De Munck J, Van Landuyt K, Lambrechts P,<br />
Peumans M. A randomized, controlled trial evaluating the three-year clinical<br />
effectiveness of two etch & rinse adhesives in cervical lesions. Oper Dent<br />
2004;29:376-385.<br />
230 The Journal of Adhesive Dentistry
Effectiveness of All-in-one Adhesive Systems Tested by<br />
Thermocycling Following Short and Long-term Water<br />
Storage<br />
Uwe Blunck a /Paul Zaslansky b<br />
Purpose: To evaluate and compare the marginal integrity of in vitro Class V restorations made with all-in-one adhesive<br />
systems by thermocycling after different periods of water storage, to provide an analysis of static and quasi-dynamic<br />
deterioration in water.<br />
Materials and Methods: Standardized Class V cavities (17 groups, 8 specimens each) were prepared in extracted<br />
human caries-free anterior teeth. The cavities were filled using 14 all-in-one adhesive systems/composite resin combinations<br />
in addition to the multi-bottle adhesive systems Syntac and OptiBond FL (etch-and-rinse technique) and<br />
Clearfil SE Bond (self-etching) as controls. The samples were thermocycled after water storage for 21 days, after 1<br />
year and again after 3 years (2000 cycles between 5 and 55°C) and replicas were made before and after each thermocycling<br />
treatment (TC) for quantitative marginal analysis in the SEM.<br />
Results: In dentin, marginal adaptation showed no significant differences between all groups after the first TC. After<br />
one year of water storage and a second TC, the results for Prompt L-Pop (1999), Adper Prompt L-Pop/Tetric Ceram,<br />
and One-up Bond F Plus showed a statistically significant decrease of margin quality 1 (MQ1) score compared to the<br />
reference groups. When the all-in-one adhesives G-Bond, AQ-Bond, Hybrid Bond, and One-up Bond F Plus were used,<br />
the enamel margins of restorations showed lower percentages of “continuous margins” (p < 0.05) after 1 year of<br />
water storage and TC. Of the materials tested after 3 years of water storage and TC, only AQ Bond had a significantly<br />
lower MQ1 score.<br />
Conclusion: While all materials exhibited deterioration in the MQ1 quality score, the rate of deterioration varied, and<br />
the results show that different materials have different deterioration rates after initial vs long-term water storage. The<br />
deterioration along margins in dentin was not as extensive as predicted from other studies; however, the results from<br />
the enamel margins show that one-bottle all-in-one adhesives seem to be significantly affected by water storage. The<br />
results of this study suggest that the all-in-one adhesive group members perform very differently from each other:<br />
thus, data need to be explored further at the level of each different adhesive product<br />
Keywords: marginal quality evaluation, in vitro Class V restorations, adhesive system effectiveness.<br />
J Adhes Dent 2007; 9: 231-240. Submitted for publication: 15.12.06; accepted for publication: 4.1.07.<br />
a Associate Professor, Charité-Universitätsmedizin Berlin, Dental School, Campus<br />
Virchow Klinikum, Berlin, Germany.<br />
b Staff Scientist, Max Planck Institute of Colloids and Interfaces, Department of<br />
Biomaterials, Potsdam, Germany<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Dr. Uwe Blunck, Charité-Universitätsmedizin Berlin, Dental<br />
School, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany.<br />
Tel: +49-30-450-562-673, Fax: +49-30-450-562-961.<br />
Adhesive systems are routinely used to improve the marginal<br />
seal of composite resin restorations at the interfaces<br />
with enamel and dentin. Bonding between enamel or<br />
dentin and the restorative composite must be sufficiently effective<br />
to resist the varying stresses to which a “typical”<br />
restoration is subjected. Such stresses include the polymerization<br />
shrinkage during composite placement as well as<br />
mechanical, thermal, and hydration stresses incurred in the<br />
oral environment due to normal use and wear. 25<br />
Available adhesive systems may be classified as dentinconditioning<br />
adhesive systems with selective acid etching<br />
on enamel, etch-and-rinse systems which necessitate phosphoric<br />
acid etching and rinsing of enamel/dentin prior to ap-<br />
Vol 9, Supplement 2, 2007 231
Blunck/Zaslansky<br />
Table 1 Tested adhesive system/composite resin combinations<br />
Group Adhesive system Composite resin Adhesive manufacturer<br />
Multi-bottle systems Syntac Artemis Ivoclar Vivadent; Schaan,<br />
(control)<br />
Liechtenstein<br />
OptiBond FL Herculite XR Kerr; Danbury, CT, USA<br />
Clearfil SE Bond Clearfil AP-X Kuraray; Tokyo, Japan<br />
All-in-one Prompt L-Pop 1999 Tetric Ceram ESPE; Seefeld, Germany<br />
adhesive systems Prompt L-Pop 2000 Tetric Ceram ESPE<br />
with mixing Adper Prompt L-Pop Tetric Ceram 3M ESPE; St Paul, MN, USA<br />
Adper Prompt L-Pop Filtek Z250 3M ESPE<br />
Futurabond NR Grandio Voco; Cuxhaven, Germany<br />
One-up Bond F Estilite Tokuyama; Tokyo, Japan<br />
Xeno III Tetric Ceram <strong>Dentsply</strong> DeTrey; Konstanz, Germany<br />
Xeno III Dyract eXtra <strong>Dentsply</strong> DeTrey<br />
Xeno III Quixfil <strong>Dentsply</strong> DeTrey<br />
All-in-one AQ Bond Metafil CX Morita; Irvine, CA, USA<br />
adhesive systems G-Bond Gradia GC; Tokyo, Japan<br />
without mixing Hybrid Bond Metafil Morita<br />
iBond Charisma Heraeus Kulzer, Hanau, Germany<br />
tri-S bond Clearfil AP-X Kuraray<br />
plying multi-bottle or one-bottle adhesives, and self-etching<br />
systems that contain acid monomers which can condition<br />
both enamel and dentin simultaneously with no rinsing. 36<br />
Self-etching adhesive systems can be applied in two consecutive<br />
steps or as so-called all-in-one adhesives. The latter<br />
are available in two forms: those that require mixing and<br />
those that do not.<br />
The effectiveness of adhesive systems can be tested in<br />
vitro by bond strength measurements of various kinds, by<br />
penetration tests of Class V/II fillings with different substances,<br />
and by evaluating the margin quality of Class I/II/V<br />
or cylindrical fillings under a microscope. 17 In this study, visual<br />
inspection of discontinuities at the margins was performed<br />
using a scanning electron microscope (SEM), dedicated<br />
to the identification and quantification of dental margin<br />
qualities. 26 This method has several advantages, such<br />
as the high level of detail revealed and marked accuracy, allowing<br />
it to be used for evaluating the same margins at different<br />
times. This is particularly useful for testing the effects<br />
of water storage or stress on the same specimens.<br />
This paper considers the effectiveness of all-in-one adhesive<br />
systems in comparison to reference multi-bottle adhesive<br />
systems, as judged by evaluating the marginal integrity<br />
in dentin and enamel after different periods of water<br />
storage. The effects of short- vs long-term storage were exemplified<br />
by applying thermal stress in order to expose marginal<br />
degradation differences. This was used to study the<br />
state of the restoration margins at 3 weeks, 1 year and 3<br />
years, and consider some aspects of the dynamics of adhesive<br />
aging.<br />
MATERIALS AND METHODS<br />
This work reflects the current status of a large ongoing study.<br />
Teeth, anonymously collected following routine dental treatment,<br />
were stored in 0.1% thymol solution at room temperature<br />
prior to and during the experimental period. One hundred<br />
thirty-six caries-free extracted human anterior teeth<br />
were used, and typical Class V cavities were prepared with<br />
a diamond bur (diamond bur No. 838/314/014; Gebr. Brasseler;<br />
Lemgo, Germany) at high speed using water as a<br />
coolant. Oval preparations were a standard size: approximately<br />
4 mm high, 1.5 mm deep, and 3 mm wide (2 mm apical<br />
to the cementoenamel junction spanning across the CEJ<br />
and into enamel). The enamel portions were bevelled with a<br />
finishing diamond bur (Composhape H-15, Intensiv; Viganello-Lugano,<br />
Switzerland) and the cavosurface margins<br />
in dentin finished to a 90-degree angle with a finishing diamond<br />
(No. 8838/314/012, Gebr. Brasseler). The teeth were<br />
randomly divided into 17 groups of 8 teeth each.<br />
Each group of teeth was assigned to one of 17 treatments.<br />
These included 14 combinations of all-in-one adhesive<br />
system/composite resins and three multi-bottle adhesive<br />
systems (Syntac and OptiBond FL, etch-and-rinse technique,<br />
and Clearfil SE Bond, self-etching technique). The adhesives<br />
were all applied and restored with composite resin<br />
according to the manufacturer’s instructions as detailed in<br />
Table 1. In an attempt to ensure optimal performance of the<br />
adhesives, the composite used was generally that recommended<br />
by the adhesive manufacturer, although for some<br />
of the adhesives (Adper Prompt L-Pop and Xeno III), several<br />
232 The Journal of Adhesive Dentistry
Blunck/Zaslansky<br />
composites were used. The composite resin was inserted in<br />
two increments (initially placed at the cervical margin), and<br />
each increment was light cured (Astralis 10 light-curing unit,<br />
Ivoclar Vivadent; Ellwangen, Germany) for 40 s. After finishing<br />
and polishing (Sof-Lex Pop-on Nr. 1981 SF/F/M/C 3M<br />
ESPE; St Paul, MN, USA), the teeth were returned to water<br />
storage for 21 days, followed by 2000 cycles of thermocycling<br />
(TC) between +5 and +55°C.<br />
Prior to and after TC, impressions were taken with a<br />
polyvinylsiloxane material (Silagum light body, DMG; Hamburg,<br />
Germany) and replicas of the restoration and surrounding<br />
tooth structures were produced. These were cast<br />
with an epoxy resin following precise manufacturer guidelines<br />
(Stycast 1266 Part A + B; Emerson and Cumming; Westerlo-Oevel,<br />
Belgium). Once fully cured, each replica was sputter-gold<br />
coated (SCD 030, Balzers Union; Balzers, Liechtenstein)<br />
in preparation for inspection by SEM. Similar impression<br />
and TC procedures were repeated after 1 year of water<br />
storage, and for 11 products also after 3 years.<br />
The effectiveness of each bonding system was assessed<br />
by evaluating the margins of the restorations at the<br />
dentin/composite and enamel/composite interface. Measurements<br />
were performed using a dedicated SEM (AMRAY<br />
1810, Amray; Bedford, MA, USA) and all replicas were viewed<br />
at a magnification of 200X, and classified according to the<br />
state of the margin in different areas in order to numerically<br />
quantify the marginal qualities, as detailed in Table 2. By<br />
using this method, each segment of the tooth/restoration interface<br />
was imaged and ranked according to defined quality<br />
criteria. These were then converted into percentage of the<br />
total margin length, in dentin and enamel independently.<br />
Statistical evaluation was performed using an SPSS statistical<br />
software package (SPSS Software; München, Germany).<br />
Within each sample group, significant differences<br />
were determined using the nonparametric Wilcoxon test. For<br />
comparison between the different treatment groups, the<br />
nonparametric Kruskal-Wallis test was used followed by Bonferroni<br />
adjustment. The statistics were calculated for the parameter<br />
margin quality 1 (MQ1 = “excellent” or “continuous”<br />
margin). Origin 7.0 SR0 (Originlab; Northampton, MA, USA)<br />
was used for the weighted regression and Microsoft Excel<br />
(2000) was used to determine the slopes between MQ1<br />
rankings at different stages of the experiment.<br />
RESULTS<br />
The results of the 14 test groups were compared with those<br />
of the 3 reference multi-bottle adhesives OptiBond FL, Syntac,<br />
and Clearfil SE Bond. Figure 1 is a box-and-whiskers plot<br />
of the marginal quality MQ1results determined for the enamel<br />
margins, depicting the median, 25 and 75 percentiles.<br />
The main result seen here is that after 1 year of water storage<br />
(Fig 1a) and following a second TC, a reduction (significant<br />
at p < 0.05) in the amounts of “continuous margins”<br />
(MQ1) is seen for G-Bond, AQ-Bond, Hybrid Bond, and Oneup<br />
Bond F Plus. No significant difference was found between<br />
any other of the groups and the reference adhesives. After<br />
3 years of water storage and a third TC, only AQ Bond had a<br />
substantially lower MQ1 score (p < 0.05).<br />
Table 2 Criteria for the marginal analysis in the SEM<br />
Margin<br />
quality<br />
Definition<br />
1 Margin not or hardly visible, no or slight marginal<br />
irregularities*; no gap<br />
2 No gap but severe marginal irregularities*<br />
3 Gap visible (hairline crack up to 2μm, no marginal<br />
irregularities*<br />
4 Severe gap (more than 2μm), slight and severe<br />
marginal irregularities*<br />
* The term "marginal irregularities" refers to porosities, marginal<br />
restoration fracture, or bulge in the restoration<br />
Figure 2 shows the MQ1 results that were obtained for<br />
each product in dentin following each of the three TC treatments.<br />
Following the first TC (Fig 2a), no statistically significant<br />
differences were found for any of the groups. The TC after<br />
1 year of water storage (Fig 2b) revealed a decrease in<br />
MQ1 for Prompt L-Pop in the 1999 version, Adper Prompt L-<br />
Pop/Tetric Ceram, and One-up Bond F Plus (p < 0.05). After<br />
three years of water storage and a 3rd TC both Prompt L-Pop<br />
(1999) and Adper Prompt L-Pop/Tetric Ceram were found to<br />
have substantially lower MQ1 scores than the reference<br />
groups (p < 0.05). Data for One-up Bond F Plus, G-Bond, AQ-<br />
Bond, Hybrid Bond, and tri-S Bond are missing for three<br />
years, as these materials were not available for the full duration<br />
of the present study.<br />
To better understand the dynamics of the results presented<br />
in Fig 2 and to obtain insights into the effects of TC<br />
and water storage, plots were produced of MQ1 for each<br />
group before and after TC at 21 days (T1 and T2), after 1 year<br />
of water storage (T3 and T4) and after 3 years of water storage<br />
(T5 and T6). Only the plots for the reference multi-bottle<br />
products are shown as examples in Fig 3. Each data point<br />
(T1-T6) represents the median MQ1 values with the corresponding<br />
error bars that are the standard error of the mean<br />
(SE). It must be emphasized that in these plots, the time intervals<br />
between the data points are not equal. The trends of<br />
the T1-T2, T2-T4, and T4-T6 segments were calculated in<br />
each graph, because the effects of water storage alone (segment<br />
T2-T3 after 1 year and segment T4-T5 after 2 additional<br />
years) were too small to be directly and reliably visualized.<br />
Thus, the purpose of TC was to challenge the bonds<br />
of the restorations in order to test the marginal integrity. Further<br />
analysis was then used to explore the joint effects of TC<br />
after the different water storage periods.<br />
The T1-T2, T2-T4, and T4-T6 slopes as well as the statistical<br />
significance (p) of the difference between each pair of the<br />
corresponding MQ1 values (obtained with the nonparametric<br />
Wilcoxon rank test) are presented in Table 3, columns A to<br />
F (shown as 1 st water storage [WS] vs 1 st TC, 1 st TC vs 2 nd TC,<br />
2 nd TC vs 3 rd TC). We also calculated trends in the overall adhesive<br />
effectiveness by fitting linear regression lines (error<br />
Vol 9, Supplement 2, 2007 233
Blunck/Zaslansky<br />
0<br />
20<br />
40<br />
60<br />
80<br />
100 %<br />
+<br />
Syntac<br />
OptiBond FL<br />
Clearfil SE Bond<br />
a.<br />
MQ1<br />
results after<br />
2 nd TC<br />
enamel<br />
+<br />
+<br />
*<br />
*<br />
*<br />
Prompt L-Pop 1999<br />
Prompt L-Pop 2000<br />
Adper Prompt L-Pop / Tetric Ceram<br />
Adper Prompt L-Pop / Filtek Z250<br />
Xeno III / Quixfil<br />
Xeno III / Tetric Ceram<br />
Xeno III / Dyract eXtra<br />
Futurabond NR<br />
One-up Bond F Plus<br />
AQ Bond<br />
iBond<br />
G-Bond<br />
Hybrid Bond<br />
tri-S bond<br />
+<br />
Syntac<br />
OptiBond FL<br />
Clearfil SE Bond<br />
b.<br />
MQ1<br />
results after<br />
3 rd TC<br />
enamel<br />
+<br />
Prompt L-Pop 1999<br />
Prompt L-Pop 2000<br />
Adper Prompt L-Pop / Tetric Ceram<br />
Adper Prompt L-Pop / Filtek Z250<br />
0<br />
20<br />
40<br />
6<br />
0<br />
80<br />
*<br />
100 %<br />
Xeno III / Tetric Ceram<br />
Xeno III / Dyract eXtra<br />
AQ Bond<br />
iBond<br />
Fig 1 Results of marginal quality<br />
1 in % relative to the enamel margin<br />
length in Class V cavities for<br />
self-etching adhesive systems<br />
after (a) 1-year water storage and<br />
a 2nd TC and (b) after after 3-<br />
year water storage and a 3rd TC<br />
(o and + = outliers, * = statistically<br />
significantly different compared<br />
to Syntac, Opti Bond FL,<br />
and Clearfil SE Bond, p < 0.05).<br />
weighted by the SE) through the six MQ1 data points for every<br />
product. The slopes of these regression lines, as well as the<br />
95% confidence intervals and r 2 values are also shown in<br />
Table 3 (columns I to L), and they provide an overall estimate<br />
of the trend for the deterioration of the MQ1 results for each<br />
product. A general linear deterioration was observed for all<br />
groups (see example plots in Fig 3), which shows that the deterioration<br />
rate is not consistent over time. Furthermore, for<br />
all the products, the overall trend (column I) only occasionally<br />
corresponds to the trend of the intermediate segments<br />
(columns A, C, E, and G in Table 3).<br />
Finally, to better understand how well the data from the<br />
first year can be used to predict the trend in the performance<br />
of each product over a period of 3 years, the trends of T1 -<br />
T4 were calculated and used to derive a percent deviation<br />
estimate relative to the regressed overall trend (the difference<br />
divided by the slope of the overall trend as %, shown in<br />
Table 3, column M). Note that for some of the products (Opti-<br />
Bond FL, AQ Bond, Prompt L Pop 2000, Adper Prompt L Pop,<br />
and Xeno III) a reasonable (≤ 10%) prediction was found,<br />
while for others, deviations of 20%, 30% or even 40% exist.<br />
DISCUSSION<br />
Effectiveness of adhesive systems can be generally judged<br />
by the marginal adaptation of composite resin restorations<br />
at the interface with the tooth substrate. Marginal adaptation<br />
is affected by many different parameters. These might<br />
be greatly influenced by the inherent properties of the<br />
restorative material, such as shrinkage and shrinkage<br />
stress, 24 the chemistry of the adhesive system used, the size<br />
234 The Journal of Adhesive Dentistry
Blunck/Zaslansky<br />
0<br />
20<br />
40<br />
60<br />
80<br />
100 %<br />
Syntac<br />
Optibond FL<br />
Clearfil SE Bond<br />
a.<br />
MQ1<br />
results after<br />
1 st TC<br />
dentin<br />
+<br />
Prompt L-Pop (1999)<br />
Prompt L-Pop (2000)<br />
Adper Prompt L-Pop / Tetric Ceram<br />
Adper Prompt L-Pop / Filtek Z250<br />
Xeno III / Dyract eXtra<br />
Xeno III / Quixfil<br />
Xeno III / Tetric Ceram<br />
Futurabond NR<br />
One Up Bond F Plus<br />
AQ Bond<br />
iBond<br />
Hybrid Bond<br />
G-Bond<br />
tri-S bond<br />
Syntac<br />
OptiBond FL<br />
Clearfil SE Bond<br />
b.<br />
MQ1<br />
results after<br />
2 nd TC<br />
dentin<br />
*<br />
*<br />
*<br />
Prompt L-Pop 1999<br />
Prompt L-Pop 2000<br />
Adper Prompt L-Pop / Tetric Ceram<br />
Adper Prompt L-Pop / Filtek Z250<br />
Xeno III / Dyract eXtra<br />
Xeno III / Quixfil<br />
Xeno III / Tetric Ceram<br />
Futurabond NR<br />
One-up Bond F-Plus<br />
AQ Bond<br />
iBond<br />
Hybrid Bond<br />
G-Bond<br />
tri-S bond<br />
Fig 2 Marginal quality 1 results<br />
in % of the dentin margin length in<br />
Class V cavities for all-in-one adhesive<br />
systems after (a) 21 days of<br />
water storage and a 1st TC, after<br />
(b) 1 year of water storage and a<br />
2nd TC, and (c) after after 3 years<br />
of water storage and a 3rd TC (o<br />
and + = outliers, * = statistically<br />
significantly different compared to<br />
Syntax, OptiBond FL, and Clearfil<br />
SE Bond p < 0.05).<br />
c.<br />
MQ1<br />
results after<br />
3 rd TC<br />
dentin<br />
0<br />
20<br />
40<br />
+<br />
6<br />
0<br />
+<br />
80<br />
*<br />
*<br />
100 %<br />
Syntac<br />
OptiBond FL<br />
Clearfil SE Bond<br />
Prompt L-Pop 1999<br />
Prompt L-Pop 2000<br />
Adper Prompt L-Pop / Tetric Ceram<br />
Adper Prompt L-Pop / Filtek Z250<br />
Xeno III / Dyract eXtra<br />
Xeno III / Tetric Ceram<br />
AQ Bond<br />
iBond<br />
of the cavity, the c-factor, 9 the insertion technique, and the<br />
polymerization protocol. 1<br />
In this study, a high resolution quantitative marginal<br />
analysis method was used to evaluate the marginal adaptation<br />
of composite resin restorations over a long period of water<br />
storage followed by TC. This quantification method relies<br />
on imaging of precision replicas of restored teeth with a<br />
scanning electron microscope, followed by quantitative quality<br />
analysis of the entire margin length. The replica technique<br />
is non-destructive to the natural-tooth samples; hence, the<br />
margins can be assessed and marginal defects detected<br />
and compared at different times, as well as after applying<br />
different stresses to the tooth specimens. The high sensitivity<br />
of this method, due to the SEM's excellent detail reproduction,<br />
is a great advantage for the evaluation of such<br />
bonding of adhesive systems. 4,26<br />
The results (Figs 1 and 2) show a distribution of the MQ1<br />
results of the restoration margins at different stages of the<br />
Vol 9, Supplement 2, 2007 235
Blunck/Zaslansky<br />
[% MQ1]<br />
100<br />
95<br />
a.<br />
90<br />
85<br />
Optibond FL<br />
80<br />
75<br />
T1 T2 T3 T4 T5 T6<br />
[% MQ1]<br />
100<br />
95<br />
b.<br />
90<br />
85<br />
Syntac<br />
80<br />
75<br />
T1 T2 T3 T4 T5 T6<br />
c.<br />
[% MQ1]<br />
100<br />
95<br />
90<br />
85<br />
80<br />
75<br />
Clearfil SE Bond<br />
T1 T2 T3 T4 T5 T6<br />
Fig 3 Median MQ1 values in % of entire margin length<br />
in dentin with error bars indicating the standard error of<br />
the mean for the multi-bottle reference materials (a) Opti<br />
Bond FL, (b) Syntac and (c) Clearfil SE Bond at the six<br />
evaluation stages T1 (after 21 days’ water storage), T2<br />
(after 1st TC), T3 (after 1 year of water storage), T4 (after<br />
2nd TC), T5 (after 3 years of water storage) and T6 (after<br />
3rd TC). Black lines: regression lines weighted by the corresponding<br />
standard error; dotted lines: 95% confidence<br />
intervals.<br />
study, but overall the scores are quite high, perhaps due to<br />
the fact that the deterioration is generally quite minimal.<br />
Further examination of the present data allows creating a<br />
quasi-dynamic perspective of the deterioration rate of the<br />
restorations (Fig 3 and Table 3). Thus it is seen that there is<br />
a general negative trend in the MQ1 values, when these are<br />
determined after water storage and/or thermocycling (TC).<br />
Clearly, the specific state of the bond between each<br />
restorative and the tooth is not easily determined by any surface-evaluation<br />
method, particularly following long-term water<br />
storage. The decision was thus made to use TC to induce<br />
mild stress to every tooth-restoration interface in order to better<br />
reveal its state as determined by the marginal quality evaluation.<br />
As can be seen in Table 3, the effect of TC is not constant<br />
during early vs late (> 1 year) water storage, and this is<br />
attributed to the differences in the adhesive stability in water.<br />
A number of publications have dealt with the effects of<br />
similar long-term water storage beyond 2 years. 2,3,7,16,22,<br />
23,27 To the best of our knowledge, however, none have managed<br />
to produce high-resolution long-term data mapping the<br />
marginal quality deterioration on the same samples.<br />
Despite the fact that the cavity dimensions were standardized,<br />
the amount of stress induced to the interface of<br />
each restoration probably varied considerably. This might<br />
be due to the large variations in the coefficients of thermal<br />
expansion of each restorative 28,29 or possibly due to tooth<br />
variability. Be that as it may, because the manufacturer-recommended<br />
composites were used, it was assumed that the<br />
conditions were optimal for each adhesive, and that the<br />
best performance was obtained. It remains to be seen if other<br />
combinations of composite/adhesive deliver improved<br />
long-term results. Possibly, a standard composite restorative<br />
should be used for such tests in the future in order to<br />
better compare the effectiveness of the investigated adhesives.<br />
The importance of the effect of the composite resins<br />
can clearly be seen in the groups of Adper Prompt L-Pop and<br />
Xeno III, where large differences in MQ1 values and slopes<br />
are seen for the same adhesive. Note however, that while<br />
Adper Prompt L-Pop in combination with Tetric Ceram<br />
showed a statistically significant decrease in MQ1 compared<br />
to the results obtained with Filtek Z250, all three<br />
combinations with Xeno III (Dyract XP, Quixfil, and Tetric Ceram)<br />
revealed no statistically significant differences in marginal<br />
integrity. We therefore conclude that these adhesives<br />
react differently to composite resins with higher polymerization<br />
shrinkage stress values.<br />
Both in vitro 6,7,10,11 and in vivo studies 8,12,13,35,37 have<br />
shown that multi-bottle multi-step adhesive systems such as<br />
236 The Journal of Adhesive Dentistry
Blunck/Zaslansky<br />
Table 3 Slopes of regression lines and statistical significance (p) of results from different evaluation stages after water storage (WS) and thermocycling (TC):<br />
columns A + B = 1 st WS vs 1 st TC, columns C + D = 1 st TC vs 2 nd TC, columns E + F = 2 nd TC vs 3 rd TC, columns G + H = 1 st WS vs 2 nd TC. Columns I to L show the<br />
slope for the regression lines for all data points of one group, r 2 -values, lower (LCI) and upper confidence intervals (UCI). The last column shows the percentage<br />
of deviation between the slopes of the overall regression lines (column I) and the regression lines between 1 st and 2 nd TC (column C). n.a. = not analyzed (data<br />
were not available after 3 years of water storage). Column M is the percent deviation calculated by the formula [100*(I col I - col G I/col I)] where col I and col<br />
G refer to values in columns I and G, resp.<br />
A B C D E F G H I J K L M<br />
1 st WS vs 1 st TC 1 st TC vs 2 nd TC 2 nd TC vs 3 rd TC 1 st WS vs 2 nd TC r 2 LCI UCI %<br />
slope p slope p slope p slope p Deviation<br />
Syntac /<br />
Artemis -2.36 0.173 -0.73 0.028 -0.53 0.028 -1.27 0.028 -0.97 0.91 -1.99 0.05 30.93<br />
OptiBond FL /<br />
Herculite XR -1.80 0.018 -1.26 0.069 -1.97 0.017 -1.44 0.017 -1.56 0.98 -2.65 -0.48 7.69<br />
Clearfil SE Bond /<br />
Clearfil AP-X 0.00 0.109 -4.33 0.018 -2.88 0.012 -1.53 0.018 -2.50 0.89 -3.41 -1.60 38.80<br />
Prompt L-Pop 1999 /<br />
Tetric Ceram -6.11 0.018 -21.99 0.012 -3.40 0.012 -16.70 0.012 -13.06 0.95 -15.45 -10.68 27.87<br />
Prompt L-Pop 2000 /<br />
Tetric Ceram -6.94 0.018 -4.01 0.093 -3.71 0.012 -4.99 0.012 -4.52 0.98 -5.80 -3.25 10.40<br />
Adper Prompt L-Pop /<br />
Tetric Ceram -6.23 0.018 -10.51 0.012 -6.17 0.012 -9.08 0.012 -8.55 0.98 -10.30 -6.81 6.20<br />
Adper Prompt L-Pop /<br />
Filtek Z250 -3.32 0.018 -3.69 0.012 -1.55 0.012 -3.56 0.012 -2.95 0.97 -3.83 -2.06 20.68<br />
Xeno III /<br />
Tetric Ceram -0.89 0.068 -2.13 0.043 -0.92 0.018 -1.72 0.028 -1.35 0.91 -2.78 0.07 27.41<br />
Xeno III /<br />
Dyract eXtra -2.61 0.043 -0.40 0.043 -0.84 0.012 -1.13 0.043 -1.09 0.92 -2.80 0.62 3.67<br />
Xeno III /<br />
Quixfil -1.77 0.138 -2.72 0.028 n.a. n.a. -2.40 0.028 -2.07 0.96 -4.65 0.51 15.94<br />
Futurabond NR /<br />
Grandio -3.83 0.028 -1.32 0.018 n.a. n.a. -2.15 0.018 -2.21 0.94 -4.34 -0.09 2.71<br />
One-up Bond F Plus/<br />
Estilite -6.43 0.012 -11.49 0.012 n.a. n.a. -9.80 0.012 -6.65 0.77 -12.77 -0.53 47.37<br />
AQ Bond /<br />
Metafil CX 0.00 0.109 -2.66 0.401 -1.60 0.069 -1.77 0.028 -1.63 0.96 -2.36 -0.90 8.59<br />
Hybrid Bond /<br />
Metafil -4.31 0.018 -1.83 0.018 n.a. n.a. -2.66 0.018 -2.62 0.95 -4.94 -0.30 1.53<br />
iBond /<br />
Charisma -0.95 0.043 -3.07 0.028 -0.95 0.012 -2.36 0.028 -1.83 0.95 -2.99 -0.68 28.96<br />
G-Bond /<br />
Gradia -4.22 0.012 -7.16 0.012 n.a. n.a. -6.18 0.012 -4.61 0.78 -8.44 -0.78 34.06<br />
tri-S Bond /<br />
Clearfil AP-X -6.20 0.012 -3.12 0.012 n.a. n.a. -4.15 0.012 -3.90 0.93 -6.03 -1.76 6.41<br />
Vol 9, Supplement 2, 2007 237
Blunck/Zaslansky<br />
a.<br />
21 days of WS vs. 1st TC<br />
multi-bottle adhesives<br />
all-in-one adhesiv es w ith mixing<br />
all-in-one adhesiv es w ithout mixing<br />
-25 -20 -15 -10 -5 0<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
AQ Bond<br />
Clearfil SE Bond<br />
Xeno III / Tetric Ceram<br />
iBond<br />
Xeno III / Quixfil<br />
OptiBond FL<br />
Syntac<br />
Xeno III / Dyract eXtra<br />
Adper Prompt L-Pop / Filtek Z250<br />
Futurabond NR<br />
G-Bond<br />
Hybrid Bond<br />
Prompt L-Pop 1999<br />
tri-S Bond<br />
Adper Prompt L-Pop / Tetric Ceram<br />
One-up Bond F Plus<br />
Prompt L-Pop 2000<br />
b.<br />
1st TC vs. 2nd TC<br />
multi-bottle adhesives<br />
all-in-one adhesiv es w ith mixing<br />
all-in-one adhesiv es w ithout mixing<br />
-25 -20 -15 -10 -5 0<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
*<br />
Xeno III / Dyract eXtra<br />
Syntac<br />
OptiBond FL<br />
Futurabond NR<br />
Hybrid Bond<br />
Xeno III / Tetric Ceram<br />
AQ Bond<br />
Xeno III / Quixfil<br />
iBond<br />
tri-S Bond<br />
Adper Prompt L-Pop / Filtek Z250<br />
Prompt L-Pop 2000<br />
Clearfil SE Bond<br />
G-Bond<br />
Adper Prompt L-Pop / Tetric Ceram<br />
One-up Bond F Plus<br />
Prompt L-Pop 1999<br />
Fig 4 Ranked slopes of regression<br />
lines through MQ1 values<br />
in dentin for each product (a)<br />
after 21 days of water storage<br />
vs 1 st TC (column A in Table 3)<br />
and (b) 1 st TC vs 2 nd TC (column<br />
C in Table 3). * denotes<br />
stopes that were determined<br />
between MQ1 median values<br />
that are statistically different<br />
with p < 0.05 (Wilcoxon test).<br />
OptiBond FL and Syntac in combination with the etch-andrinse<br />
technique and the multi-step self-etching adhesive<br />
Clearfil SE Bond are reliable adhesives even after long-term<br />
usage. For this reason, these three products were used as<br />
reference materials in this study. They also provide to some<br />
extent a means to calibrate the present results with other<br />
studies. With the quasi-dynamic trends, it is possible to rank<br />
the different adhesives according to their rate of deterioration<br />
(as shown for mainly after TC) after 21 days or 1 year in<br />
water (see example Figs 4a and 4b). This ranking differs for<br />
the two water storage periods, which can be attributed to the<br />
specific properties of each adhesive, which lead to differences<br />
in bond quality and rates of degradation.<br />
The working assumption of this study was that better performance<br />
of any adhesive group would be associated with<br />
the highest (least negative) slope of MQ1 deterioration (column<br />
I in Table 3). These slope values are different from the<br />
slopes of the individual segments 1st WS vs 1st TC and 1st<br />
vs 2nd TC, and thus the rate of deterioration of the bonds<br />
might vary substantially over time. As seen in Figs 4a and 4b,<br />
238 The Journal of Adhesive Dentistry
Blunk/Zaslansky<br />
many of the products, change the rank between the initial<br />
water storage period, as compared with the rank after the<br />
first year . We are aware that such ranking might be of limited<br />
use for predicting clinical performance; therefore, clinicians<br />
and manufacturers might need to define criteria for<br />
“adequate performance”, not “better performance”. Clearly<br />
such long-term effects need to be considered in addition to<br />
operation skill and experience, 15,21 both of which are difficult<br />
to account for, therefore consequences of these findings<br />
necessitate further investigations.<br />
The marginal analysis centered on the quantitative evaluation<br />
of MQ1 (“excellent” or “continuous” margin) as a<br />
measure for marginal integrity. It has recently been shown<br />
that such an evaluation provides a good indicator for the<br />
ability of an adhesive system to compensate for the shrinkage<br />
of composite resins during polymerization, as compared<br />
to bond strength tests. 17 The extent to which the present in<br />
vitro results correspond to in vivo data of quantitative marginal<br />
analysis of Class V fillings is not obvious, especially as<br />
there are reports showing that such data are unable to predict<br />
clinical outcome. 17 Nevertheless, results of this study<br />
and trend analysis provide an additional means of determining<br />
objective and standard measures of the physical attributes<br />
of any combination of adhesive system and composites.<br />
It therefore remains to be seen just how such details<br />
match the outcomes of clinical investigations. It is worthwhile<br />
to note that other studies have evaluated the marginal<br />
quality using stress induced by mechanical loading. 12,13<br />
The method employed in this study has the advantage that<br />
TC induces precise and repeatable stress (assuming the coefficient<br />
of thermal expansion of the composites stays constant),<br />
and this concept was used to provide more information<br />
about the effects of water storage at short and long intervals.<br />
The present results are based on SEM evaluation of the<br />
percentage of the different marginal qualities, calculated in<br />
relation to the entire margin length in dentin or enamel independently.<br />
It has been shown that when the same operator<br />
evaluates the same specimens twice, the difference between<br />
the results is in the range of 4%, 26 whereas when two<br />
trained operators evaluate the same specimens, the differences<br />
can reach 10% to 20%. 18 Therefore, all specimens in<br />
this study were prepared and evaluated by the same operator.<br />
It is interesting to note that for most of the products not<br />
displaying a large discrepancy between the initial and intermediate<br />
MQ1 values, the first-year data provide only a moderate<br />
predictor for the longer term trend of deterioration.<br />
Therefore, initial predictors of restorative success have limited<br />
applicability, and more data over long periods of time<br />
are needed. This is unavoidable even in an in vivo setting,<br />
and is important especially when both manufacturers and<br />
clinicians want to know as early as possible which is the best<br />
product. It is, of course, conceivable that storage at higher<br />
temperatures might allow faster answers to these questions.<br />
All-in-one adhesives are rather user friendly; however, certain<br />
indicators have suggested reduced performance that<br />
might be associated with their usage. Compared with twostep<br />
self-etching or etch-and-rinse adhesive systems, lower<br />
bond strength values were reported. 5,14,19,20 It has also<br />
been shown that permeable membranes develop after curing<br />
due to a high hydrophilicity, which allows water movements<br />
through the all-in-one adhesive layer. 30 Sites of incomplete<br />
water removal and subsequent suboptimally polymerized<br />
resins 31 have been described and termed “water<br />
trees”. All these might contribute to extensive degradation<br />
of the adhesive layer, 7,32 but conclusive findings have not<br />
been confirmed. The most recent (to date) one-bottle all-inone<br />
adhesives appear to be susceptible to phase separation<br />
after dispensing the complex mixture of hydrophobic and hydrophilic<br />
components, 34 and this also is assumed to contribute<br />
to bond degradation. 33<br />
This study has presented preliminary results of short- and<br />
long-term water storage effects combined with thermocycling<br />
for control and 14 all-in-one adhesive/composite treatments.<br />
The results show that overall, few if any differences<br />
are found in vitro between the tested products and the reference<br />
materials. Furthermore, based on a quality estimate<br />
associated with the marginal integrity, it has been shown<br />
that early deterioration rates (up to 1 year) can only sometimes<br />
be used as estimates for the rate of bond degradation<br />
over a period of 3 years. Indeed, it seems that deterioration<br />
rates due to storage in water are not dependent on the class<br />
(or generation) of the adhesive: large differences in deterioration<br />
rates seem to exist between different products, and<br />
these are probably associated with the details of the specific<br />
chemistry. Additional studies are still needed in order to<br />
elucidate to what extent – and in which product – deterioration<br />
is critical. These should then be correlated with clinical<br />
studies so that decisive conclusions can be drawn .<br />
It appears that the effects of long-term water storage may<br />
not be as detrimental as usually assumed, if indeed the marginal<br />
integrity estimates are appropriate measures of the<br />
quality and effectiveness of recent generations of dental adhesives.<br />
A statistically significant decrease in the amount of<br />
MQ1 was only found in 3 out of 14 tested all-in-one adhesives<br />
after 1 year water storage. However, in enamel, the<br />
marginal analysis revealed fewer “continuous margins” than<br />
the control groups for G-Bond, AQ Bond, Hybrid Bond, and<br />
One-up Bond F Plus, and this was already observed after 1<br />
year of water storage.<br />
As new results of clinical evaluations emerge, and with a<br />
growing body of data from in vitro measurements, it is hoped<br />
that a clearer understanding of the long-term effects of the<br />
use of these systems will emerge, thus providing an improved<br />
guide for clinical judgement.<br />
REFERENCES<br />
1. Anusavice KJ. Criteria for selection of restorative materials: properties versus<br />
technique sensitivity. In: Anusavice KJ (ed). Quality evaluation of dental<br />
restorations. Chicago: Quintessence, 1989:15-56.<br />
2. Armstrong SR, Vargas MA, Fang Q, Laffoon JE. Microtensile bond strength<br />
of a total-etch 3-step, total-etch 2-etch, self-etch 2-step, and a self-etch 1-<br />
step dentin bonding system through 15-month water storage. J Adhes Dent<br />
2003;5:47-56.<br />
3. Armstrong SR, Vargas MA, Chung I, Pashley DH, Campbell JA, Laffoon JE,<br />
Qian F. Resin-dentin interfacial ultrastructure and microtensile dentin bond<br />
strength after five-year water storage. Oper Dent 2004;29-26:705-712.<br />
Vol 9, Supplement 1, 2007 239
Blunck/Zaslansky<br />
4. Blunck U, Roulet JF. In vitro marginal quality of dentin-bonded composite<br />
resins in Class V cavities. Quintessence Int 1989;20:407-412.<br />
5. Bouillaguet S, Gysi P, Wataha JC, Ciucchi B, Cattani M, Godin C, Meyer JM.<br />
Bond strength of composite to dentin using conventional, one-step, and<br />
self-etching adhesive systems. J Dent 2001;29:55-61.<br />
6. De Munck J, Van Meerbeek B, Satoshi I, Vargas M, Yoshida Y, Armstrong S,<br />
Lambrechts P, Vanherle G. Microtensile bond strengths of one- and twostep<br />
self-etch adhesives to bur-cut enamel and dentin. Am J Dent 2003;<br />
16:414-420.<br />
7. De Munck J, Van Meerbeek B, Yoshida Y, Inoue S, Vargas M, Suzuki K,<br />
Lambrechts P, Vanherle G. Four-year water degradation of total-etch adhesives<br />
bonded to dentin. J Dent Res 2003;82:136-140.<br />
8. De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem<br />
M, van Meerbeek B. A critical review of the durability of adhesion to tooth<br />
tissue: methods and results. J Dent Res 2005;84:118-132.<br />
9. Feilzer AJ, De Gee AJ, Davidson CL. Setting stress in composite resin in relation<br />
to configuration of the restoratives. J Dent Res 1987;66:1636-1639.<br />
10. Frankenberger R, Krämer N, Petschelt A. Fatigue behaviour of different<br />
dentin adhesives. Clin Oral Invest 1999;3:11-17.<br />
11. Frankenberger R, Perdigão J, Rosa BT, Lopes M. 'No-bottle' vs 'multi-bottle'<br />
dentin adhesives - a microtensile bond strength and morphological study.<br />
Dent Mater 2001;17:373-380.<br />
12. Frankenberger R, Pashley DH, Reich SM, Lohbauer U, Petschelt A, Tay FR.<br />
Characterisation of resin-dentine interfaces by compressive cyclic loading.<br />
Biomat 2005;26:2043-2052.<br />
13. Frankenberger R, Tay FR. Self-etch vs etch-and-rinse adhesives: effect of<br />
thermo-mechanical fatigue loading on marginal quality of bonded resin<br />
composite restoration. Dent Mater 2005;21:397-412.<br />
14. Fritz UB, Finger WJ. Bonding efficiency of single-bottle enamel/dentin adhesives.<br />
Am J Dent 1999;12:277-282.<br />
15. Giachetti L, Russo DS, Bertini F, Pierleoni F, Nieri M. Effect of operator skill<br />
in relation to microleakage of total-etch and self-etch bonding systems J<br />
Dent 2006;in press:<br />
16. Hashimoto M, Ohno H, Sano H, Kaga H, Oguchi H. Degradation patterns of<br />
different adhesives and bonding procedures. J Biomed Mater Res<br />
2003;66B:324-330.<br />
17. Heintze SD. The correlation between the evaluation of marginal quality and<br />
bond strength and its clinical relevance – a systematic review. J Adhes<br />
Dent 2007;9(Suppl 1):77-106<br />
18. Henisch G. Ein computergestütztes System zur Erfassung und Verwaltung<br />
von Messdaten im Rahmen der quantitativen Randanalyse am Rasterelektronenmikroskop.<br />
Berlin: Free University, 1989.<br />
19. Inoue S, Vargas MA, Abe Y, Yoshida Y, Lambrechts P, Vanherle G, Sano H,<br />
Van Meerbeek B. Microtensile bond strength of eleven contemporary adhesives<br />
to dentin. J Adhes Dent 2001;3:237-245.<br />
20. Inoue S, Vargas MA, Abe Y, Yoshida Y, Lambrechts P, Vanherle G, Sano H,<br />
Van Meerbeek B. Microtensile bond strength of eleven contemporary adhesives<br />
to enamel. Am J Dent 2003;16:329-334.<br />
21. Jacobsen T, Söderholm KJ. Effect of primer solvent, primer agitation, and<br />
dentin dryness on shear bond strength to dentin. Am J Dent 1998;11:225-<br />
228.<br />
22. Kato G, Nakabayashi N. The durability of a adhesion to phosphoric acid<br />
etched, wet dentin substrates. Dent Mater 1998;14:347-352.<br />
23. Kitasako Y, Burrow MF, Nikaido T, Tagami J. Long-term tensile bond durability<br />
of two different 4-META containing resin cements to dentin. Dent Mater<br />
2002;18:276-280.<br />
24. Peutzfeldt A, Asmussen E. Determinants of in vitro gap formation of resin<br />
composites. J Dent 2004;32:109-115.<br />
25. Retief DH. Do adhesives prevent microleakage Int Dent J 1994;44:19-26.<br />
26. Roulet JF, Reich T, Blunck U, Noack M. Quantitative margin analysis in the<br />
scanning electron microscope. Scanning Microsc 1989;3:147-158; discussion<br />
58-59.<br />
27. Sano H, Yoshikawa T, Pereira PNR, Kanemura N, Morigami M, Tagami J,<br />
Pashley DH. Long-term durability of dentin bonds made with a self-etching<br />
primer, in vivo. J Dent Res 1999;78:906-911.<br />
28. Sideridou I, Achilias DS, Kyrikou E. Thermal expansion characteristics of<br />
light-cured dental resins and resin composites. Biomat 2004;25:3087-<br />
3097.<br />
29. Sidhu SK, Carrick TE, McCabe JF. Temperature mediated coefficient of dimensional<br />
change of dental tooth-colored restorative materials. Dent<br />
Mater 2004;20:435-440.<br />
30. Tay FR, Pashley DH, Suh BI, Carvalho RM, Itthagarun A. Single-step adhesives<br />
are permeable membranes. J Dent 2002;371-382.<br />
31. Tay FR, Pashley DH, Yoshiyama M. Two modes of nanoleakage expression<br />
in single-step adhesives. J Dent Res 2002;81:472-476.<br />
32. Tay FR, Pashley DH. Water treeing--a potential mechanism for degradation<br />
of dentin adhesives. Am J Dent 2003;16:6-12.<br />
33. Van Landuyt K, De Munck J, Coutinho E, Peumans M, Lambrecht P, Van<br />
Meerbeek B. Bonding to dentin: smear layer and the process of hybridization.<br />
In: Eliades G, Watts DC, Eliades T (eds). Dental hard tissues and<br />
bonding. Berlin: Springer, 2005:89-122.<br />
34. Van Landuyt KL, De Munck J, Snauwaert J, Coutinho E, Poitevin A, Yoshida<br />
Y, Inoue S, Peumans M, Suzuki K, Lambrechts P, Van Meerbeek B.<br />
Monomer-solvent phase separation in one-step self-etch adhesives. J Dent<br />
Res 2005;84:183-188.<br />
35. Van Meerbeek B, Perdigao J, Lambrechts P, Vanherle G. The clinical performance<br />
of adhesives. J Dent 1998;26:1-20.<br />
36. Van Meerbeek B, De Munck J, Yoshida Y, Inoue S, Vargas M, Vijay P, Van<br />
Landuyt K, Lambrechts P, Vanherle G. Buonocore memorial lecture. Adhesion<br />
to enamel and dentin: current status and future challenges. Oper<br />
Dent 2003;28:215-235.<br />
37. van Meerbeek B, Kanumilli P, de Munck J, Van Landuyt K, Lambrechts P,<br />
Peumans M. A randomized controlled study evaluating the effectiveness of<br />
a two-step self-etch adhesive with and without selective phosphoric-acid<br />
etching of enamel. Dent Mater 2005;21:375-383.<br />
Clinical relevance: Quantitative in vitro long-term measurements<br />
of margin integrity help to better understand<br />
the performance of composite resin restorations in the<br />
clinic. In combination with clinical studies this should<br />
provide a deeper understanding of the adhesive failure<br />
an which remains enormous challenge for dentists.<br />
240 The Journal of Adhesive Dentistry
Clinical Bonding of a Single-step Self-etching Adhesive<br />
in Noncarious Cervical Lesions<br />
Jan WV van Dijken a /Karin Sunnegårdh-Grönberg b /Ebba Sörensson b<br />
Purpose: The aim of this study was to evaluate the clinical retention to dentin of a single-step self-etching adhesive<br />
system.<br />
Materials and Methods: A total of 133 Class V restorations were placed with the self-etching primer Xeno III and a<br />
resin composite (Tetric Ceram) or a polyacid-modified resin composite (Dyract AP) in noncarious cervical lesions without<br />
intentional enamel involvement. The restorations were evaluated at baseline and then every 6 months during a 2-<br />
year follow-up. Dentin bonding efficacy was determined by the percentage of lost restorations.<br />
Results: During the 2 years, 130 restorations could be evaluated. The cumulative loss rate at 2 years was 7.7%, with<br />
no significant differences between the two restorative materials. The self-etching adhesive fulfilled the 18-month full<br />
acceptance ADA criteria.<br />
Conclusion: The single-step self-etching adhesive showed acceptable clinical retention rates to dentin surfaces during<br />
the evaluation period independent of restorative material used.<br />
Keywords: adhesion, clinical, cervical, dental material, etch, resin, restoration, self-etching.<br />
J Adhes Dent 2007; 9: 241-243. Submitted for publication: 15.12.06; accepted for publication: 8.1.07.<br />
a Professor, Department of Odontology, Dental School Umeå, Umeå University,<br />
Umeå, Sweden.<br />
b Assistant Professor, Department of Odontology, Dental School Umeå, Umeå University,<br />
Umeå, Sweden.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Prof. Jan WV van Dijken, Department of Odontology, Dental<br />
School Umeå, Umeå University , 901 87 Umeå, Sweden. Tel: +46-90-785-6034,<br />
Fax: +46-90-770-580. e-mail: Jan.van.Dijken@odont.umu.se<br />
The introduction of primers containing amphiphilic monomers<br />
– dissolved in solvents such as water, acetone, or<br />
alcohol to promote wetting of the dentin and replace water<br />
– changed dentin bonding to a more reliable clinical procedure.<br />
These primers infiltrate the nanospaces of the collagen<br />
network, caused by the etching procedure, and create<br />
after polymerization an entangled molecular mesh with the<br />
collagen fibrils. 4 A high micromechanical bond to the dental<br />
tissue can be obtained by formation of the so-called hybrid<br />
layer. In the multistep etch-and-rinse systems, clinical success<br />
is partly operator related. The etching and primer application<br />
steps are critical in this approach. Bonding procedures<br />
not involving phosphoric acid etching, such as the selfetching<br />
adhesives, were introduced in the 90s to simplify the<br />
adhesive procedure and decrease the technique sensitivity<br />
of the etch-and-rinse systems. The simultaneous self-etching<br />
and primer infiltration makes these systems more user<br />
friendly, eliminating the risk of over etching and over drying.<br />
Today, there are two self-etching systems. The two-step selfetching<br />
adhesives have a separate priming step with more<br />
hydrophilic monomers and a more hydrophobic bonding<br />
step. In the all-in-one or one-step self-etching adhesives, one<br />
liquid containing all the components for etching, priming,<br />
and bonding is applied to the dental tissues. Earlier mild selfetching<br />
adhesives showed etching patterns of the enamel<br />
which were not adequate for clinical retention, and some<br />
manufacturers recommended the adjunctive use of phosphoric<br />
acid when bonding to enamel. 5 Incompatibility with<br />
autocuring resin composites and permeability to water<br />
movement after polymerization have been reported for the<br />
first all-in-one adhesives. 14,15 Newer self-etching adhesives<br />
contain more aggressive etchants and showed higher tensile<br />
bond strength compared to established dentin bonding<br />
agents. 7 The aim of this study was to investigate the clinical<br />
dentin bonding effectiveness of a new one-step self-etching<br />
adhesive in combination with a resin composite material or<br />
a polyacid resin-modified resin composite in noncarious cer-<br />
Vol 9, Supplement 2, 2007 241
van Dijken et al<br />
Fig 1 Relative cumulative loss rates<br />
(%) of the Xeno III bonding system in<br />
combination with the two restorative<br />
materials (Tetric Ceram, Dyract AP).<br />
vical lesions. The hypothesis tested was that the polyacid<br />
resin-modified resin composite would show better clinical retention.<br />
MATERIALS AND METHODS<br />
A total of 133 Class V restorations were placed in 57 patients<br />
(32 men and 25 women) with a mean age of 61.5 years<br />
(range 43 to 84), for whom treatment of noncarious cervical<br />
lesions was indicated. All restorations were placed in dentin<br />
lesions without any intentional enamel involvement, by one<br />
experienced operator familiar with adhesive dentistry. Fortyfour<br />
restorations were placed in anterior teeth, 55 in premolars<br />
and 32 in molars. Fifty-nine restorations were made<br />
in the maxillary arch and 74 in the mandibular. A single-step<br />
self-etching primer (Xeno III, <strong>Dentsply</strong>/DeTrey; Konstanz,<br />
Germany; lot nr 0206001237) was evaluated in combination<br />
with two different restorative resinous materials, a hybrid<br />
resin composite (Tetric Ceram, Ivoclar/Vivadent;<br />
Schaan, Liechtenstein; lot E17820) and a polyacid-modified<br />
resin composite (Dyract AP, <strong>Dentsply</strong>/DeTrey; batch nr<br />
0203001190). Liquid A of the two-part adhesive system<br />
contains water, ethanol, HEMA, UDMA and BHT (2,6-di-tertbutyl-p<br />
hydroxyl toluene) and nanofiller. Liquid B contains<br />
UDMA, CQ, EPD (p-dimethylaminoethyl benzoate) and two<br />
patented monomers Pyro-EMA (tetramethacryloxyethyl pyrophosphate<br />
and PEM-F (pentamethacryloxyethyl cyclophosphazene<br />
monofluoride).<br />
The operative field was isolated with cotton rolls and a<br />
saliva suction device. Before conditioning, the lesions were<br />
cleaned of plaque and/or saliva if necessary. The adjacent<br />
gingiva was retracted by gingival retraction instruments or<br />
matrix bands when necessary to secure unrestricted contamination-free<br />
access to the field. No bevel was placed. Application<br />
of the primer was performed according to the manufacturers’<br />
instructions. After mixing, the primer was applied<br />
for 20 s, carefully air dried for some seconds to remove<br />
the solvent, taking care not to thin the primer layer. The layer<br />
was then light cured for at least 10 s (Astralis 7, HP curing<br />
mode; Ivoclar/Vivadent). Sixty-five restorations were<br />
made at random with the polyacid resin-modified resin composite<br />
and 68 with a high-viscosity resin composite restorative<br />
material. The restoratives were applied in most cases in<br />
two increments using selected composite instruments (Hu<br />
Friedy; Leimen, Germany) and light cured. All participants<br />
were informed about the material and the follow-up evaluations<br />
according to the rules at the Dental School Umeå. The<br />
restorations were evaluated at 6, 12, 18, and 24 months using<br />
slightly modified USPHS criteria. 3,5 Only the retention<br />
evaluations are reported here. Postoperative sensitivity was<br />
registered. Descriptive statistics were used to present the results.<br />
Cumulative retention failures were calculated by dividing<br />
the number of lost restorations at the recalls by the<br />
total number evaluated at the respective recall. Differences<br />
in distribution of the ratings between the adhesive systems<br />
for the investigated variables were statistically analyzed with<br />
the binomial test for independent samples and intraindividual<br />
comparisons of the 2 materials with Friedman’s two-way<br />
analysis of variance. 13<br />
RESULTS<br />
At the end of the follow-up, 130 restorations could be evaluated.<br />
One patient with three restorations was not able to attend<br />
the 2-year recall. No recurrent caries was observed or<br />
postoperative sensitivity reported. Ten lost restorations<br />
(7.7%) were observed during the 2-year follow-up, resulting<br />
in relative cumulative failure frequencies for all restorations<br />
at 6, 12, 18, and 24 months of 0.8%, 3.1%, 6.9%, and 7.7%,<br />
respectively. The failure frequencies for the restorations with<br />
Tetric Ceram at the four evaluations were 0%, 0%, 5.9%, and<br />
7.4%, and for Dyract AP restorations 1.6%, 6.5%, 8.1%, and<br />
8.1%, respectively; the differences were not statistically significant<br />
(Fig 1).<br />
242 The Journal of Adhesive Dentistry
van Dijken et al<br />
DISCUSSION<br />
The rapid progression of adhesive materials during the last<br />
20 years has resulted in a situation where many adhesive<br />
systems have been replaced by modified successors which<br />
were claimed to be better without clinical validation. Clinical<br />
trials have been limited in number since they require several<br />
years of regular recalls. Enamel-resin bonds produced after<br />
acid etching with phosphoric acid have proven satisfactory<br />
and stable over time. 2,5,6 Adhesion to dentin, on the other<br />
hand, has been difficult to achieve because of the substrate’s<br />
wet nature. The efficacy of dentin bonding can be<br />
demonstrated in cervical abrasion/erosion lesions without<br />
involvement of the contiguous enamel. These surfaces are<br />
ideal to test clinical dentin bonding because they are widely<br />
available. 12 Therefore, no enamel bevel was made in the<br />
study and care was taken not to involve the enamel surface<br />
contiguous with the lesions during the etching-priming step.<br />
However, many of the lesions still contained a small enamel<br />
margin in the incisal area, and the evaluation of clinical<br />
retention to only dentin tissue was therefore not 100%. At<br />
the end of the two years, the recall rate was high (130/133).<br />
The retention rate for the adhesive system was 92.3%.<br />
Türkün recently reported a 96% retention rate after one year<br />
for the same adhesive. 16 For provisional acceptance, the latest<br />
guidelines of the American Dental Association (Dental<br />
and enamel adhesive materials: ADA, Council on Dental Materials,<br />
Instruments, and Equipment, 1994) for submission<br />
of dentin and enamel adhesive materials require that no<br />
more than 5% of the restorations have been lost and not<br />
more than 5% of the restorations may show microleakage at<br />
the 6-month recall. To obtain full acceptance, the cumulative<br />
incidence of clinical failures in each of two independent clinical<br />
studies has to be lower than 10% lost restorations and<br />
10% microleakage after 18 months. The dentin retention<br />
rates for the tested adhesive were 3.1% and 6.9% at 6 and<br />
18 months, respectively, fulfilling the ADA guidelines for<br />
enamel-dentin adhesive systems. There were no significant<br />
differences in clinical retention rates between the restorations<br />
placed with the resin composite or the polyacid-modified<br />
resin composite. The hypothesis was therefore not accepted.<br />
Kemp-Scholte et al 8 showed that materials with lower<br />
elasticity modulus can act as an elastic buffer, which relieved<br />
contraction stresses and improved marginal integrity.<br />
Since most polyacid-modified resin composites include<br />
resins with a modulus of elasticity value between those of<br />
resin composite and glass-ionomer cement, these materials<br />
may work as a stress-breaking barrier between the tooth and<br />
the composite. 1 A significantly better adaptation was observed<br />
with the SEM replica technique for a polyacid-modified<br />
resin composite/resin composite sandwich technique<br />
compared to resin composite only restorations. 9 However,<br />
the same authors could not show any clinical evidence for<br />
the interfacial adaptation results observed by SEM. No significant<br />
statistical or clinical differences were observed between<br />
the two techniques during 3- and 9-year periods. 10,11<br />
The polyacid-modified resin composite tested in the present<br />
study has a modulus of elasticity value close to that of resin<br />
composite materials, which may partly explain why no differences<br />
were observed (personal communication, E. Asmussen).<br />
CONCLUSION<br />
It can be concluded that the single-step self-etching adhesive<br />
showed acceptable clinical retention rates during the<br />
evaluation period, independent of restorative material used.<br />
ACKNOWLEDGMENTS<br />
This study was supported in part by the County Council of Västerbotten<br />
and <strong>Dentsply</strong> DeTrey, Konstanz, Germany.<br />
REFERENCES<br />
1. Attin T, Vataschki M, Hellwig E. Properties of resin-modified glass-ionomer<br />
restorative materials and two polyacid-modified resin composite materials.<br />
Quintessence Int 1996;27:203-209.<br />
2. de Munck J, van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem M,<br />
van Meerbeek B. A critical review of the durability of adhesion to tooth tissue:<br />
methods and results. J Dent Res 2005;84:118-132.<br />
3. Dijken van JWV. A clincial evaluation of anterior conventional, microfiller and<br />
hybrid composite resin fillings. A six year follow up study. Acta Odont Scand<br />
1986;44:357-367.<br />
4. Dijken van JWV. Multi-step versus simplified enamel-dentin bonding systems-<br />
Réalités Cliniques 1999;10:199-222.<br />
5. Dijken van JWV. Durability of new restorative materials in Class III cavities. J<br />
Adhes Dent 2001;3:65-70.<br />
6. Frankenberger R, Krämer N, Petschelt A. Long term effect of dentin primers<br />
on enamel bond strength and marginal adaptation. Oper Dent 2000;25:11-<br />
19.<br />
7. Gernhardt CR, Biesecke G, Schaller HG. Tensile bond strength of a self-conditioning<br />
dentin adhesive system in vitro [abstract 338]. J Dent Res<br />
2003;82:B 55.<br />
8. Kemp-Scholte CM, Davidson CL. Marginal integrity related to bond strength<br />
and strain capacity of composite resin restorative systems. J Prosth Dent<br />
1990;64:658-664.<br />
9. Lindberg A, Dijken van JWV, Hörstedt P. Interfacial adaptation of a Class II<br />
polyacid-modified resin composite/ resin composite laminate restoration in<br />
vivo. Acta Odont Scand 2000;58:77-84.<br />
10. Lindberg A, van Dijken JWV, Lindberg M. A 3-year evaluation of a new open<br />
sandwich technique in class II cavities. Am J Dent 2003;15:33-36.<br />
11. Lindberg A, van Dijken JWV, Lindberg M. 9-year evaluation of a poly-acid-modified<br />
resin composite open sandwich technique in class II cavities. J Dent<br />
2007;35:124-129.<br />
12. Peumans M, Kanumilli P, De Munck J, van Landuyt K, Lambrechts P, van<br />
Meerbeek B. Clinical effectiveness of contemporary adhesives: A systematic<br />
review of current clinical trials. Dent Mater 2005;21:864-881.<br />
13. Siegel S. Nonparametric Statistics. New York: McGraw-Hill, 1956.<br />
14. Tay FR, Pashley DH. Water-treeing – a potential mechanism for degradation<br />
of dentin adhesives. Am J Dent 2003;16:6-12.<br />
15. Tay FR, Pashley DH, Yiu CKY, Sanares AME, Wei SHY. Factors contributing to<br />
the incompatibility between simplified-step adhesives and self-cured or dualcured<br />
composites. Part I. Single-step self-etch adhesive. J Adhes Dent<br />
2003;5:27-40.<br />
16. Türkün LS. The clinical performance of one- and two-step self-etching adhesive<br />
systems at one year. J Am Dent Assoc 2005;136:656-664.<br />
Clinical relevance: The adhesive showed a good clinical<br />
performance during the 2 year follow-up in noncarious cervical<br />
lesions.<br />
Vol 9, Supplement 2, 2007 243
Sarrett<br />
244 The Journal of Adhesive Dentistry
Shear Bond Strength and Physicochemical Interactions<br />
of XP Bond<br />
Mark A. Latta a<br />
Purpose: The purpose of this study was to evaluate the shear bond strength of composite to dentin and enamel using<br />
the new etch-and-rinse adhesive XP Bond compared to other adhesives (Optibond Solo Plus, Apder ScotchBond 1 XT,<br />
Syntac Classic).<br />
Materials and Methods: Shear bond strength (MPa) was measured by shearing a resin cylinder 4.5 mm in diameter<br />
from prepared buccal surfaces of human third molars using an Instron Testing Machine equipped with a chiselshaped<br />
rod. In addition, micro-Raman spectroscopy was performed to determine if there was a chemical interaction<br />
between the resin adhesive and dentin and enamel.<br />
Results: Significant differences were observed among the dentin and enamel values generated with the adhesives<br />
tested. XP Bond generated statistically similar values to Optibond Solo Plus and Apder ScotchBond 1 XT to both<br />
enamel and dentin. Syntac Classic generated significantly lower values to both enamel and dentin.<br />
Conclusion: Micro-Raman spectroscopy showed a complete infiltration of resin into the demineralized dentin zone. In<br />
addition, it strongly suggested a chemical interaction with XP Bond and components of dentin. It is hypothesized that<br />
this interaction is due to the formation of calcium phosphate complexes derived from mineral apatite in the dentin<br />
and phosphate esters in the adhesive.<br />
Keywords: adhesion, bonding, chemical analysis, Raman spectroscopy.<br />
J Adhes Dent 2007; 9: 245-248. Submitted for publication: 15.12.06; accepted for publication: 11.1.07.<br />
In spite of significant improvements in dental adhesives in<br />
the last decade, achieving a durable bond and seal of<br />
resin based restorative materials still remains a challenge.<br />
The primary mechanism for bonding to dentin with etch-andrinse<br />
adhesives is via the removal of the dentin smear layer<br />
and surface mineral followed by infiltration and entanglement<br />
of resin monomers into the exposed collagen matrix in<br />
the demineralized zone. 2 This resultant mixture of resin, collagen,<br />
and mineral is termed the hybrid zone. 4 The exposed<br />
collagen fibrils are suspended in water, creating space for<br />
a Associate Dean for Research, Professor of General Dentistry, Creighton University<br />
School of Dentistry, Omaha NE, USA.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Prof. Mark A. Latta, D.M.D., M.S., Associate Dean for Research,<br />
Professor of General Dentistry, Creighton University School of Dentistry,<br />
2500 California Plaza, Omaha NE 68178, USA. Tel: +1-402-280-5044, Fax: +1-<br />
402-280-5004. e-mail: mlatta@creighton.edu<br />
the penetration of the resin monomers. Drying collagen results<br />
in its collapse and may prevent full infiltration of the adhesive<br />
resin. 3 Clinically, it is difficult to create the optimal<br />
dentin moisture for bonding. However, failure to do so may<br />
lead to postoperative sensitivity, bond failure, leakage, and<br />
ultimately early failure of the restoration.<br />
There are numerous in-vitro testing methods to evaluate<br />
the properties of resin adhesives. While bond strength testing<br />
does not definitively predict clinical behavior, comparison<br />
of new systems with adhesives of known clinical performance<br />
can yield valuable information. 1,5,9 Microscopically,<br />
the interfacial interaction between adhesive and tooth structure<br />
is typically investigated with scanning electron microscopy<br />
and transmission electron microscopy. However,<br />
there is only limited chemical structural investigation of the<br />
resin/tooth interface. The minimal thickness of the<br />
tooth/adhesive interface requires an analytical technique<br />
with very high resolution. Micro-Raman spectroscopy has<br />
been shown to be a very promising technique for investigating<br />
the adhesive bond with tooth structure. 7,8,10,11 It has numerous<br />
advantages, including the ability to analyze speci-<br />
Vol 9, Supplement 2, 2007 245
Latta<br />
Table 1 Mean shear bond strength (SBS) for each group (in MPa)<br />
Bonding Agent Mean SBS to dentin (MPa) Mean SBS to enamel (MPa)<br />
Optibond Solo plus 26.5 ± 2.9 28.3 ± 4.8<br />
XP Bond 25.8 ± 2.6 28.3 ± 4.7<br />
Adper Scotchbond 1 XT 24.2 ± 3.4 26.5 ± 4.9<br />
Syntac Classic (15-s etch) 13.2 ± 3.7* 21.6 ± 5.8*<br />
* Significantly different compared to the other groups (p < 0.05)<br />
mens in air or water, at room temperature and pressure, and<br />
without destroying the specimen.<br />
A new etch-and-rinse adhesive called XP Bond has been<br />
developed that has several unique compositional components.<br />
It is hypothesized that these components will allow<br />
the adhesive formula to be less sensitive to residual dentin<br />
moisture and allow full resin penetration under a wide range<br />
of dentin conditions. Second, this adhesive contains phosphate<br />
esters that may chemically interact with the mineral<br />
apatite component of dentin and enamel. The purpose of<br />
this study was to evaluate the shear bond strength of composite<br />
to dentin and enamel using this new adhesive system.<br />
In addition, micro-Raman spectroscopy was performed to<br />
determine if there was a chemical interaction between the<br />
resin adhesive and dentin and enamel.<br />
MATERIALS AND METHODS<br />
Shear Bond Strength<br />
Flat bonding sites were prepared on the buccal surfaces of<br />
96 extracted human teeth by grinding the teeth on a watercooled<br />
abrasive wheel (Ecomet III Grinder, Lake Bluff, IL,<br />
USA) to a 600-grit surface exposing dentin on 48 specimens<br />
and enamel on 48 specimens. Twelve specimens each for<br />
enamel and dentin for each adhesive were prepared. The adhesives<br />
and conditions of use were:<br />
• Group 1: XP Bond (lot 0503004020) cured for 10 s with<br />
the SmartLite LED curing light.<br />
• Group 2: Optibond Solo Plus (lot 437041) cured for 10 s<br />
with the SmartLite LED curing light.<br />
• Group 3: Adper Scotchbond 1 XT (lot 230270) for 10 s<br />
with the SmartLite LED curing light.<br />
• Group 4: Syntac Classic (lot G06551) using phosphoric<br />
acid etch 15 s and cured for 10 s with the SmartLite LED<br />
curing light.<br />
DeTrey tooth conditioner (<strong>Dentsply</strong> Detrey; Konstanz, Germany;<br />
lot 0403000687) was used to condition all surfaces<br />
prior to placement of the adhesive. After the application of<br />
the adhesive system, cylinders of composite resin (Spectrum<br />
TPH Shade A2, lot 0411002236; <strong>Dentsply</strong> DeTrey; Konstanz,<br />
Germany) were bonded to each dentin and enamel<br />
bonding site. A gelatin capsule technique in which a resin<br />
cylinder 4.5 mm in diameter is employed as a matrix was<br />
used. Composite was loaded in the capsules approximately<br />
two-thirds full, then cured in a Triad 2000 curing unit (Trubyte<br />
Division, DENTSPLY International; York, PA, USA) for 1 min.<br />
Additional composite was added to slightly overfill the capsules.<br />
The capsules were firmly seated against the bonding<br />
sites and excess resin removed with a dental explorer. The<br />
resin was visible-light cured with three 20-s curing sequences,<br />
each from opposite sides of the capsule at an angle<br />
of 45 degrees to the tooth surface.<br />
The specimens were stored in distilled water at 37°C for<br />
24 h. Twelve specimens for each adhesive/tooth structure<br />
combination were thermocycled between water baths of 5°C<br />
and 55°C for 6000 cycles (dwell time 20 s). The specimens<br />
were mounted in acrylic and loaded to failure in an Instron<br />
Testing Machine (Model 1123, Instron; Canton, MA, USA)<br />
equipped with a chisel-shaped rod. Each bonded cylinder<br />
was placed under continuous loading at 5 mm per min until<br />
fracture occurred. Shear bond strength was calculated in<br />
MPa.<br />
Raman Spectroscopy<br />
Extracted third molars were prepared by grinding enamel<br />
and dentin to a 600-grit surface. The experimental adhesive<br />
was applied and composite resin placed over the adhesive<br />
film. After water storage, the teeth were sectioned to expose<br />
the tooth/adhesive interface and polished to 4000 grit with<br />
silicon carbide paper. Specimens were placed on an X-Y<br />
scanning stage in a Jasco 3100 laser Raman Spectrometer<br />
(Jasco; Tokyo, Japan). The excitation was derived from a<br />
785-nm source at an output level of 35 mW and focused<br />
through an X100 near-IR lens to ~ 1 μm beam diameter.<br />
Wavenumber calibration was determined by comparison of<br />
spectra from pure silicon (520 cm -1 ).<br />
RESULTS AND DISCUSSION<br />
Shear Bond Strength<br />
The mean shear bond strength (in MPa) for each group is displayed<br />
in Table 1. A one-way ANOVA was done for the dentin<br />
and enamel groups. The level of significance for dentin was<br />
p < 0.0001, and for enamel p = 0.0168. A post-hoc LSD test<br />
was done for pair-wise comparison. The group marked by an<br />
asterisk was statistically different compared to the other<br />
groups (p < 0.05).<br />
246 The Journal of Adhesive Dentistry
Latta<br />
Fig 1 Representative spectra of dentin (left) and dentin impregnated with XP Bond (right). Circle represents peak shift and broadening in<br />
the 1100 to 1170 cm -1 range is suggestive of calcium-phosphate ester complex formation.<br />
Fig 2 Representative spectrum of XP Bond showing major functional<br />
groups. Plot of peak intensity vs wavenumber cm -1 .<br />
Fig 3 Peak intensity for characteristic marker peaks for dentin,<br />
mineral and resin are plotted across the dentin/adhesive interface.<br />
The resin peak at 1720 cm -1 fully penetrates to the bottom<br />
of the demineralized zone. In addition, the maximum strength of<br />
the 1146 cm -1 peak is offset from the resin, indicating an interaction<br />
with components in the dentin layer.<br />
Raman Spectroscopy<br />
A representative spectrum of XP Bond is shown in Fig 1. Representative<br />
Raman spectra of human dentin and resin impregnated<br />
dentin with XP Bond are shown in Fig 2. The most<br />
intense band occurs at 960 cm -1 and is associated with the<br />
P-O stretch of the phosphate in the mineral apatite. Also observed<br />
are bands at 1245 cm -1 (amide III) and 1667 cm -1<br />
(amide I) associated with collagen. The mixture shown on the<br />
right clearly shows the apatite and amide I peaks mixed with<br />
features only associated with the adhesive. The peak shift<br />
and broadening in the 1100 to 1170 cm -1 area is not seen<br />
in the pure dentin or XP Bond spectrum, and is associated<br />
with the formation of calcium/phosphate ester complexes in<br />
the hybrid layer. 6<br />
The relative peak intensities of the mineral apatite (960<br />
cm -1 ), resin carbonyl (1720 cm -1 ), collagen (1670 cm -1 ), and<br />
phosphate complex (centered at 1146 cm -1 ) were plotted<br />
across the dentin interface and are shown graphically in<br />
Fig 3. The strength of the phosphate complex intensity in the<br />
intermediate hybrid layer is strongly suggestive of a chemical<br />
interaction between components in the resin adhesive<br />
and the dentin. In addition, the resin is fully penetrated to<br />
the depth of the zone of demineralization.<br />
CONCLUSION<br />
Significant differences in shear bond strength were observed<br />
among the dentin and enamel values generated with<br />
the adhesives tested. XP Bond generated statistically similar<br />
values to Optibond Solo Plus and Apder ScotchBond 1 XT<br />
to both enamel and dentin. Syntac Classic generated significantly<br />
lower values to both enamel and dentin.<br />
Micro-Raman spectroscopy showed a complete infiltration<br />
of resin into the demineralized dentin zone. In addition,<br />
it strongly suggested a chemical interaction with XP Bond<br />
Vol 9, Supplement 2, 2007 247
Latta<br />
and components of dentin. It is hypothesized that this interaction<br />
is the formation of calcium phosphate complexes derived<br />
from mineral apatite in the dentin and phosphate esters<br />
in the adhesive.<br />
ACKNOWLEDGMENTS<br />
This research was partly sponsored by <strong>Dentsply</strong> DeTrey, Konstanz,<br />
Germany.<br />
6. Penel G, Leroy N, Rey C, Lemaitre J, Van Landuyt P, Ghanty N. Qualitative<br />
and quantitative investigation of calcium phosphate of biological interest<br />
by Raman micro-spectrometry. Recent Res Develop Appl Spectroscopy<br />
1999;2:137-146.<br />
7. Sato M, Miyazaki M. Comparison of depth of dentin etching and resin infiltration<br />
with single-step adhesive systems. J Dent 2005;22:475-484.<br />
8. Spencer P, Wang Y, Walker MP, Wieliczka DM, Swafford JR. Interfacial<br />
chemistry of the dentin/adhesive bond. J Dent Res 2000;79:1458-1463.<br />
9. Shaddy RS, Latta MA, Goren M. The effect of salivary contamination on adhesive<br />
shear bond strength. J Pract Hygiene 2003;12:27-28.<br />
10. Wang Y, Spencer P. Hybridization efficiency of the adhesive dentin interface<br />
with wet bonding. J Dent Res 2003;82:141-145.<br />
11. Wang Y, Spencer P. Physicochemical interactions at the interface between<br />
self-etch adhesive systems and dentine. J Dent 2004;32:567-579.<br />
REFERENCES<br />
1. Barkmeier WW, Hamesfahr PD, Latta MA. Bond strength of composite to<br />
enamel and dentin using Prime and Bond 2.1. Oper Dent 1999;24:51-56.<br />
2. Eick JD, Gwinnet AJ, Pashley DH, Robinson SJ. Current concepts in adhesion<br />
to dentin. Crit Rev Oral Biol Med 1997;8:306-335.<br />
3. Gwinnett AJ. Quantitative contribution of resin infiltration/hybridization to<br />
dentin bonding. Am J Dent 1993;6:7-9.<br />
4. Nakabayashi N, Kijima K, Masuhara E. The promotion of adhesion by the<br />
infiltration of monomers into tooth substrates. J Biomed Mater Res<br />
1982;16:265-273.<br />
5. Naughton WT, Latta MA. Bond strength of composite to dentin using selfetching<br />
adhesive systems. Quintessence Int 2005;36:41-44.<br />
Clinical relevance: The laboratory bond values for a<br />
newly developed etch and rinse adhesive system would<br />
suggest exellent clinical performance. The discovery of<br />
chemical interaction between the adhesive and the mineral<br />
component of tooth structure may help explain the<br />
high bond strengths and also might predict the generation<br />
of a stable long term bond interface clinically.<br />
248 The Journal of Adhesive Dentistry
Microshear Fatigue Testing of Tooth/Adhesive<br />
Interfaces<br />
Marc Braem a<br />
Purpose: The objective of the present study was to determine the fatigue resistance of several contemporary dentin<br />
adhesives as well as a resin-modified glass-ionomer cement.<br />
Materials and Methods: Cyclic loading of the adhesive interface was achieved by a microshear fatigue setup following<br />
a staircase approach, where the stress level at which 50% of the specimens fail after 10 4 cycles was calculated<br />
as the median microshear fatigue resistance (μSFR).<br />
Results: For all products tested, the μSFR was lower than the microshear strength. A wide spread in μSFR was observed,<br />
ranging from 24% to 76% of the quasi-static microshear strength, irrespective of the type of adhesive used.<br />
Conclusion: The results of this study show that the microshear test setup is a discriminative and reproducible way of<br />
testing tooth/adhesive interfaces, even at relatively low stresses. The results clearly indicate that such interfaces are<br />
vulnerable to progressive damage by cyclic loads. Further, at present there is not one bonding approach, whether<br />
“total etch” or “self-etching”, that consistently yields higher fatigue resistance: the product factor seems to be of primary<br />
importance.<br />
Keywords: fatigue, dental adhesive, dynamic testing.<br />
J Adhes Dent 2007; 9: 249-253. Submitted for publication: 15.12.06; accepted for publication: 5.1.07.<br />
The success of bonding restorative materials to tooth tissue<br />
is generally expressed as a statically or quasi-statically<br />
determined strength value. Under clinical circumstances,<br />
however, tooth-restorative bonds are subjected to<br />
cyclic loads that could well induce failure at stress levels significantly<br />
lower than the ultimate bond strength, a phenomenon<br />
defined as fatigue. 1 In addition, under fatigue conditions,<br />
the influence of imperfections in the adhesive interface<br />
is more clearly revealed. 7 At present, research on<br />
dentin bonding is, among other things, focused on reducing<br />
the number of application steps in the bonding procedure,<br />
thereby assuming a reduction in the risk of defects. In vitro<br />
a Professor, Head of Lab Dental Materials, University of Antwerpen, Antwerpen,<br />
Belgium.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Dr. Marc Braem, Lab Dental Materials, Groenenborgerlaan<br />
171, B-2020 Antwerpen, Belgium. Tel: +32-3-265-32-66, Fax: +32-3-265-<br />
36.35. e-mail: marc.braem@ua.ac.be<br />
fatigue testing of these interfaces could therefore better allow<br />
studying these effects.<br />
Hence, the objective of this study was to determine the<br />
fatigue resistance of several contemporary dental adhesives<br />
and a resin-modified glass-ionomer cement bonded to<br />
dentin, using a custom-built microshear fatigue testing device.<br />
MATERIALS AND METHODS<br />
Materials<br />
The materials used are shown in Table 1. All tests were performed<br />
prior to the expiration date mentioned in the table.<br />
The composite restorative used with dentin bonding was<br />
Clearfil AP-X (Universal Shade A3, Lot 1043 BA; Kuraray,<br />
Japan). All applications were performed as per manufacturer’s<br />
instructions.<br />
Dentin Specimen Preparation<br />
Dentin collected after extraction of human third molars was<br />
used. The teeth were stored immediately in chloramine 0.5%<br />
Vol 9, Supplement 2, 2007 249
Braem<br />
Table 1 Materials used<br />
Brand name Manufacturer Type Primer Adhesive Light-curing resin<br />
Batch Exp Date Batch Exp Date Batch Exp Date<br />
Fuji II LC Capsules GC Europe glass-ionomer cement 301241 2005-01<br />
Syntac Vivadent 3-step etch and rinse G01297 2006-05 G04548 2006-08 G03430 2009-01<br />
Optibond FL Kerr 3-step etch and rinse 403204 2006-01 402145 2005-06<br />
Optibond Solo Plus Kerr 2-step etch and rinse 3-1325 2005-11<br />
Prime & Bond NT <strong>Dentsply</strong> DeTrey 2-step etch and rinse 0503000835 2008-02<br />
XP Bond <strong>Dentsply</strong> DeTrey 2-step etch and rinse 503004020 2005-11<br />
Adper ScotchBond 1 XT 3M ESPE 3-step etch and rinse 4AG 20040424 2007-02<br />
Clearfil SE Bond Kuraray 2-step SE 41460 2008-02<br />
Clearfil Protect Bond Kuraray 2-step SE 61112 2005-12<br />
Xeno III <strong>Dentsply</strong> DeTrey 1-step SE 2 components 0512000738 2007-11<br />
Adper Prompt-L-Pop 3M ESPE 1 step SE 2 components 175425 2005-09<br />
G-Bond GC Europe 1 step SE 1 component 0406161 2006-06<br />
iBond Heraeus-Kulzer 1 step SE 1 component 010082 2008-08<br />
at 5°C prior to cutting, which was done within 30 days after<br />
extraction.<br />
After removal of the roots and pulp tissue, the teeth were<br />
glued on a cubic clamp and a first cut (Microslice 2, Metals<br />
Research; Cambridge, UK) was made parallel to the occlusal<br />
surface to remove the occlusal enamel. Next, the clamp was<br />
rotated 90 degrees and a first series of parallel cuts 3 mm<br />
apart was made perpendicular to the surface. The clamp<br />
was then again rotated 90 degrees and a new series of cuts<br />
was made in an identical way. As a result, cubic samples are<br />
created that are broken off the remains of the tooth in order<br />
to make sure that perpendicularly cut tubules will be used<br />
in the test.<br />
The dentin cube was then positioned in the center of the<br />
base of the test jig with the test surface against a Plexiglas<br />
plate (Fig 1), immobilized by slight pressure. A light-curing<br />
glass-ionomer cement (Fuji II LC capsules, GC Europe; Haasrode,<br />
Belgium) was mixed for 10 s followed by 3 s in a RotoMix<br />
device (3M ESPE; Seefeld, Germany), applied without<br />
prior conditioning of the dentin, and light cured for 20 s each<br />
at the bottom and top surfaces using a QTH light source<br />
(Luxor, ICI; Manchester, UK) with an output of at least 520<br />
mW/cm 2 . Output was checked with a radiometer (Optilux<br />
Model 100, SDS Kerr; Danury, CT, USA).<br />
The dentin test surface was prepared using a small piece<br />
of 600-grit grinding paper, cleaned with compressed air and<br />
water, and thereafter visually inspected under a light microscope.<br />
The test surface was then treated according to the<br />
manufacturer’s instructions for the respective materials.<br />
When separate acid etching was required, a phosphoric acid<br />
gel was used (Scotchbond etching gel, 3M ESPE), except<br />
when a proprietary etchant is included with the adhesive, as<br />
is the case for Prime & Bond NT. Polyacrylic acid (GC Conditioner,<br />
GC Europe) was used in case of the resin-modified<br />
glass-ionomer cement.<br />
Once the final adhesive layer was finished for the dentin<br />
bonding, or the dentin was conditioned prior to the application<br />
of the resin-modified glass-ionomer cement, a perforated<br />
(diameter 1 mm) Mylar strip (0.05 mm thick) was accurately<br />
centered on top of the prepared sample and the upper<br />
part of the test jig was fixed (Fig 2). A first portion of the<br />
restorative was applied without touching the cavity walls and<br />
light cured. Next the remainder of the cavity was filled and<br />
cured incrementally.<br />
The test jig was then transferred to the fatigue machine<br />
and the screws removed (Fig 3). This method prevents the<br />
adhesive interface from being unintentionally touched or<br />
loaded by any means prior to testing.<br />
Fatigue Testing<br />
The present method is a modification of a previously described<br />
setup. 2 All testing was carried out at 35°C under<br />
load-controlled conditions, at a test frequency of 2 Hz.<br />
First, the quasi-static microshear strength (τ) was determined<br />
by measuring the maximal force at failure divided by<br />
the bonding surface area, which was measured under a light<br />
microscope prior to testing.<br />
During the fatigue test, the specimens were subjected to<br />
cyclic loading. Tests were conducted sequentially, with the<br />
initial stress set at about 50% of the microshear strength of<br />
250 The Journal of Adhesive Dentistry
Braem<br />
Fig 1 Positioning of the dentin sample with the surface to be<br />
tested oriented downwards on a Plexiglas plate.<br />
Fig 2 Top view of the test jig after preparation of the bond and<br />
placement of the perforated Mylar strip. The upper part of the jig<br />
is fixed prior to the application of the restorative material.<br />
the adhesive maximum and stressed until failure or 10 4 cycles.<br />
The applied stress in each succeeding test was increased<br />
or decreased by a fixed increment of stress, according<br />
to whether the previous test resulted in failure or no<br />
failure, also described as a staircase approach. 6 This fixed<br />
increment is based on pilot testing and fixed at 8% of the microshear<br />
strength.<br />
The results of the fatigue test were analyzed using logistic<br />
regression 4 to determine the load at which 50% of the<br />
specimens fail, further referred to as the “median microshear<br />
fatigue resistance” or μSFR. To compare the fatigue<br />
data obtained from the different experimental groups, a multiple<br />
logistic regression analysis was conducted (Statistica<br />
6.0, StatSoft; Tulsa, OK, USA).<br />
RESULTS<br />
The microshear strength and the μSFR for each material are<br />
given in Table 2. The μSFR was about 43% lower than the respective<br />
microshear strength value (Table 2), ranging from<br />
24% in the case of Optibond Solo Plus and iBond, up to 76%<br />
for Clearfil Protect Bond.<br />
Comparing the slope β 1 obtained from the logistic regression<br />
(Table 2), a very steep curve can be seen for Xeno III<br />
(β 1 = 6.5079) and Adper Prompt-L-Pop (β 1 = 5.8161), being<br />
almost 10 times steeper than that of the other resin bonding<br />
agents. In Xeno III, failures were noted after 145, 915, 196,<br />
565, 645, 1465 and 460 cycles and after 245, 1625, 150,<br />
1080, 550, 3595 and 270 cycles for Adper Prompt-L-Pop.<br />
The same can be said, although to a lesser degree, of Fuji II<br />
LC (β 1 = 1.1195) with failures at 75, 30, 65, 185, 55, 6750,<br />
40, 565, 7540, 50, and 80 cycles. G-Bond on the other hand<br />
shows a rather flat curve with β 1 = 0.1652, with failures noted<br />
at 65, 130, 135, 4430, 9475, 260, 55, and 155 cycles.<br />
Using the results from the logistic regression, the 25%<br />
Fig 3 Placement of the test jig in the fatigue machine. The jig is<br />
fixed using compressed air (1). The piezo-electric force transducers<br />
(2) record the applied loads.<br />
and 75% quartiles can be calculated, giving an indication of<br />
the range of the results around the μSFR (Table 2). Comparing<br />
the different adhesives using multiple logistic regression,<br />
the bond strength in MPa (p < 0.0001) as well as<br />
the adhesive (p = 0.0003) contribute significantly to the<br />
model.<br />
DISCUSSION<br />
The lack of fatigue data in the dental literature on adhesive<br />
interfaces is profound. Only some data are available today,<br />
4,5,7,10,12,13 in spite of the necessity to complete the quasi-static<br />
bond strength tests with clinically relevant dynamic<br />
fatigue data. A prerequisite is that the setup is of clinical rel-<br />
Vol 9, Supplement 2, 2007 251
Braem<br />
Table 2 Results for the microshear strength (τ, MPa) and μSFR (MPa)<br />
Brand name μ-shear ± SD μSFR 25% 75% β0 1 β1 1 p-value 2 τ/μSFR<br />
strength quartile quartile (%)<br />
Fuji II LC Caps 10.1 ± 3.1 4.1 3.1 5.1 -4.5580 1.1195 0.0000 41<br />
Syntac 55.5 ± 5.1 30.4 28.4 32.4 -16.6834 0.5492 0.0000 55<br />
Optibond FL 56.9 ± 3.2 17.2 13.4 21.0 -4.9682 0.2893 0.1056 30<br />
Optibond Solo Plus 49.2 ± 10.5 11.9 9.7 14.1 -6.1994 0.5188 0.0001 24<br />
Prime & Bond NT 47.0 ± 2.7 18.3 13.9 22.7 -4.5571 0.2491 0.3987 39<br />
XP Bond 56.4 ± 2.0 30.3 26.7 33.8 -9.3190 0.3081 0.0000 52<br />
Adper ScotchBond 1 XT 51.7 ± 4.8 17.9 15.7 20.1 -8.7526 0.4895 0.0585 35<br />
Clearfil SE Bond 35.0 ± 8.4 20.7 16.4 24.9 -5.3315 0.2577 0.5672 65<br />
Clearfil Protect Bond 42.8 ± 12.3 32.6 28.9 36.3 -9.7454 0.2991 0.0000 76<br />
Xeno III 46.2 ± 3.5 25.2 25.1 25.4 -175.7207 6.9613 0.0073 55<br />
Adper Prompt-L-Pop 53.5 ± 10.7 22.7 22.5 22.9 -132.0255 5.1610 0.0585 42<br />
G-Bond 54.9 ± 3.7 15.3 8.5 22.1 -2.4908 0.1625 0.0318 28<br />
iBond 51.0 ± 8.3 12.3 8.7 15.9 -3.7347 0.3042 0.0003 24<br />
1) β0 and β1 are parameters of the logistic regression function, determining the probability of failure in terms of stress applied to the interface (S): Y = exp(β0 + β1 •S) / (1 + exp(β0 + β1 •S))<br />
2) p-value of estimate of the multiple logistic regression<br />
evance. Assuming 3 periods of 15 min of chewing per day<br />
at a chewing rate of 1 Hz, the number of chews is 2700 per<br />
day. 14 This amounts to roughly 10 6 times per year. At this frequency,<br />
a fatigue test on 1 sample takes about 12 days to<br />
accomplish 10 6 cycles. Increasing the rate to 2 Hz will offer<br />
a time-saving approach well within the frequency dependency<br />
range of the tested visco-elastic materials. Furthermore,<br />
if the noncontact events are eliminated from the<br />
chewing cycles, it can be calculated that 10 4 cycles represents<br />
about 1.2 months of continuous real-life contact. This<br />
approach is justified, since restorations tend to fail either<br />
early, before 10 4 cycles, or very late, after 10 5 cycles. 9 Moreover,<br />
a test run on a sample that does not fail now takes<br />
about 1.5 h to complete, as opposed to about 1 week for<br />
10 6 cycles.<br />
A common standard in the analysis of fatigue data is the<br />
value at which 50% of the specimens fail after a pre-set number<br />
of cycles. 2,4,5 However, in the present type of fatigue testing,<br />
considerable errors can be made as to the determination<br />
of the so-called pre-set stress levels due to geometry errors. 4<br />
Therefore, the probability of failure at each applied stress level<br />
was approximated by logistic regression where the μSFR<br />
represents the value at which 50% of the specimens fail. Calculating<br />
the 25% and 75% quartiles further illustrates the<br />
distribution of the obtained data (Table 2). It can be seen<br />
from these data that the products with the steepest slopes<br />
(β 1 ) show the lowest distribution around the μSFR.<br />
Some of the adhesives therefore show a so-called type 2<br />
fatigue behavior 10 and appear to have a rather well-defined<br />
fatigue stress level or threshold above which they fail rapidly<br />
and below which they will survive (Xeno III, Adper Prompt-<br />
L-Pop, Fuji II LC). In other products, such as G-Bond, the opposite<br />
behavior is found and a wide spread of data around<br />
the μSFR can be noted. Most of the materials show a mixed<br />
type of behavior, indicating that imperfections and defects<br />
probably determine the actual lifespan of the adhesive<br />
bond. Fractographic analysis needs to be carried out to test<br />
this hypothesis.<br />
The main advantage of the present method is that with<br />
the same setup, both shear strength and fatigue resistance<br />
can be measured and compared. It is also advantageous<br />
that the method requires no processing of the sample once<br />
the interface has been formed, thereby avoiding operator-induced<br />
defects. The results show that the μSFRs are consistently<br />
lower than the respective microshear strength for the<br />
same adhesive (Table 2). This is not surprising, since it is<br />
known that internal interfacial defects and imperfections<br />
shorten the lifespan of a joint under cyclic fatigue. Hence,<br />
fatigue data generally vary substantially more than static<br />
bond strengths. 8 The present results, however, show in<br />
some cases that the variation in the fatigue data is lower<br />
than that present in the quasi-static data, thereby emphasizing<br />
the need for nontraumatic sample preparation.<br />
It is beyond the scope of the present article to discuss in<br />
full the possible mechanism of each individual adhesive related<br />
to the measured μSFR. The present results emphasize<br />
that within each type of adhesive, products exist that show<br />
a high fatigue resistance. Furthermore, some few-step adhesives<br />
perform better than other multi-step ones, while for<br />
others it is just the opposite. Thus, not only the reduction in<br />
252 The Journal of Adhesive Dentistry
Braem<br />
the number of steps but also the degree of difficulty of the<br />
step appears to be of primary importance.<br />
The present results indicate that the fatigue behavior of<br />
each individual adhesive must be carefully studied, since<br />
within each group results can be found that outperform<br />
and/or are similar to results obtained by particular adhesives<br />
in other groups. This indicates that, in general, the different<br />
types of bonding approaches converge to adequate<br />
results. In this context, the result for the glass-ionomer cement<br />
is surprising: both the microshear bond strength and<br />
the μSFR are among the lowest measured in this study. This<br />
can be explained by a mismatch in the mechanical properties<br />
of the glass-ionomer matrix and the glass particles,<br />
causing large stresses to accumulate at their interface. 11<br />
However, the clinical performance of these materials under<br />
the right indications is still remarkably good, thus supporting<br />
the hypothesis that “self-healing” or “repair” might be<br />
possible in glass-ionomer cements, 3 although such “healing”<br />
may rather be retardation in crack growth or a crack<br />
growth toughening mechanism due to the plasticizing effect<br />
of the resinous component.<br />
CONCLUSION<br />
Tooth/adhesive interfaces suffer from the progressive damage<br />
induced by subcritical cyclic loads. The differing approaches<br />
to achieving tooth-resin bonding are not consistently<br />
reflected in differences in fatigue resistance.<br />
ACKNOWLEDGMENTS<br />
The author thanks the manufacturers for the generous donation of materials.<br />
Thanks also to Dr. Jan De Munck, Leuven BIOMAT Research<br />
Cluster K.U. Leuven, Belgium, the statistical analysis could be performed.<br />
Finally, the supporting efforts and constructive criticism of Mr.<br />
Geert Keteleer, Lab Dental Materials – Universiteit Antwerpen, are<br />
greatly acknowledged.<br />
This research was partly sponsored by <strong>Dentsply</strong> DeTrey, Konstanz,<br />
Germany.<br />
REFERENCES<br />
1. Baran GR, Boberick KG, McCool JI. Fatigue of restorative materials. Crit<br />
Rev Oral Biol Med 2001;12:350-360.<br />
2. Braem M, Davidson CL, Lambrechts P, Vanherle G. In vitro flexural fatigue<br />
limits of dental composites. J Biomed Mater Res 1994;28:1397-1402.<br />
3. Davidson CL. Glassionomer bases under posterior composites. J Esthet<br />
Dent 1994;6:223-226.<br />
4. De Munck J, Braem M, Wevers M, Yoshida Y, Inoue S, Suzuki K, Lambrechts<br />
P, Van Meerbeek B. Micro-rotary fatigue of tooth-biomaterial interfaces.<br />
Biomater 2005;26:1145-1153.<br />
5. Dewji HR, Drummond JL, FadaviS, Punwani I. Bond strength of bis-GMA<br />
and glass ionomer pit and fissure sealants using cyclic fatigue. Eur J Oral<br />
Sci 1998;6:594-599.<br />
6. Draughn RA. Compressive fatigue limits of composite restorative materials.<br />
J Dent Res 1979;58:1093-1096.<br />
7. Givan DA, Fitchie JG, Anderson L, Zardiackas LD. Tensile fatigue of 4-META<br />
cement bonding three base metal alloys to enamel and comparison to<br />
other resin cements. J Prosthet Dent 1995;73:377-385.<br />
8. Hawbolt EB, MacEntee MI. Effects of fatigue on a soldered base metal<br />
alloy. J Dent Res 1983;62:1226-1228.<br />
9. Huysmans MCDNJM, Van der Varst PGT, Schäfer R, Peters MCRB, Plasschaert<br />
AJM, Soltész U. Fatigue behavior of direct post-and-core-restored<br />
premolars. J Dent Res 1992;71:1145-1150.<br />
10. McCabe JF, Carrick TE, Chadwick RG, Walls AWG. Alternative approaches<br />
to evaluating the fatigue characteristics of materials. Dent Mater<br />
1990;6:24-28.<br />
11. Nakajima H, Watkins JH, Arita K, Hanaoka K, Okabe T. Mechanical properties<br />
of glass ionomers under static and dynamic loading. Dent Mater<br />
1996;12:30-37.<br />
12. Nikaido T, Kunzelmann K-H, Chen H, Ogata M, Harada A, Yamaguchi Y, Cox<br />
CF, Hickel R, Tagami J. Evaluation of thermal cycling and mechanical loading<br />
on bond strength of a self-etching primer system to dentin. Dent Mater<br />
2002;18:269-275.<br />
13. Ruse ND, Shew R, Feduik D. In vitro fatigue testing of a dental bonding system<br />
on enamel. J Biomed Mater Res 1995;29:411-415.<br />
14. Wiskott HWA, Nicholls JI, Belser UC. Fatigue resistance of soldered joints:<br />
A methodological study. Dent Mater 1994;10:215-220.<br />
Clinical relevance: Repetitive shear loading off freshly<br />
placed adhesive fillings will impose subcritical loads<br />
that could finally induce damage and/or loss of the adhesion.<br />
The study of such behavior is therefore of utmost<br />
importance in order to gain knowledge on this<br />
type of failure<br />
Vol 9, Supplement 2, 2007 253
Sarrett<br />
254 The Journal of Adhesive Dentistry
Microleakage of Class V Composite Restorations Placed<br />
with Etch-and-Rinse and Self-etching Adhesives Before<br />
and After Thermocycling<br />
Juan Ignacio Rosales-Leal a<br />
Purpose: To evaluate the sealing ability of etch-and-rinse and self-etching adhesives in Class V cavities before and<br />
after thermocycling in vitro.<br />
Materials and Methods: Etch-and-rinse adhesives (Prime & Bond NT [P&B], XP Bond [XPB], ScotchBond 1 XT [SBX],<br />
Syntac [SYN]) and self-etching adhesives (Xeno III [XNO], i-Bond [IBO], Clearfil SE Bond [CLF]) were used. A microleakage<br />
test was performed to evaluate marginal sealing. Seventy molars were divided into seven groups according to the<br />
adhesive used. Class V cavities were restored and each group was divided into two subgroups. One group was water<br />
immersed for 24 h and the other was thermocycled. Then, specimens were immersed in fuchsin and sectioned. Microleakage<br />
and dentin permeability were recorded on occlusal and gingival walls and data were statistically analyzed.<br />
Results: Etch-and-rinse adhesives provided perfect occlusal sealing. Self-etching adhesives obtained slight occlusal<br />
leakage. In the gingival wall, XNO and CLF showed the lowest leakage, followed by XPB and SBX, then P&B. SYN and<br />
IBO exhibited the highest leakage. All SE adhesives and XPB provided sealed dentinal tubules. Thermocycling did not<br />
affect the occlusal sealing but reduced the gingival sealing when P&B, SYN, XNO, CLF, and IBO were used.<br />
Conclusion: In enamel, marginal leakage was prevented when phosphoric acid was used. Self-etching adhesives promoted<br />
slight occlusal leakage. The gingival sealing was poorer than the occlusal sealing. XNO, CLF followed by XPB<br />
obtained the best gingival sealing. Thermocycling did not affect the occlusal bonding but reduced the gingival sealing,<br />
except when XPB and SBX were used.<br />
Keywords: adhesives, Class V sealing, thermocycling, in vitro.<br />
J Adhes Dent 2007; 9: 255-259. Submitted for publication: 15.12.06; accepted for publication: 3.1.07.<br />
Sealing of a cavity is one of the most important requirements<br />
for the durability of a composite restoration. 13 Microleakage<br />
of a restoration may be the starting point of secondary<br />
caries and the treatment failure. 11 The bond needs<br />
to be hermetic but also durable over time. 3,21<br />
In vitro microleakage tests offer very useful data about<br />
the sealing behavior of adhesives. A microleakage test provides<br />
information about the sealing of the interface and the<br />
dentin tubule sealing (dentin permeability). 1,16 Results are<br />
close to clinical reality because extracted human teeth and<br />
clinical protocols are used. 7,11<br />
Two different classes of adhesives are currently used.<br />
Etch-and-rinse adhesives require a separate acid-etching<br />
step prior to the adhesive infiltration that promotes an aggressive<br />
substrate treatment. 15 Self-etching adhesives etch<br />
and infiltrate at the same time, but their acidity is less than<br />
that of phosphoric acid, resulting in less etching depth. 19<br />
More information is necessary about the sealing ability of<br />
current adhesives (etch-and-rinse vs self-etching) and the effect<br />
of aging on the durability of the sealing. The purpose of<br />
this work was to evaluate the in vitro sealing ability of etchand-rinse<br />
and self-etching adhesives in Class V cavities before<br />
and after thermocycling.<br />
a Assistant Professor, Department of Stomatology (Dental Materials), University<br />
of Granada, Granada, Spain.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Dr. Juan Ignacio Rosales-Leal, Camino de Ronda, 57-2ºB,<br />
18004 Granada, Spain. Tel: + 34-653-32-03-84, Fax: +34-958-240-908.<br />
e-mail: irosales@ugr.es<br />
MATERIALS AND METHODS<br />
The adhesives used are described in Table 1. Seventy third<br />
molars were divided into 7 groups as a function of the adhesive<br />
used (Table 1). In each specimen, two Class V Cavities<br />
(3 x 2 x 2 mm [depth] with a 1-mm 45-degree enamel<br />
Vol 9, Supplement 2, 2007 255
Rosales-Leal<br />
Table 1 Materials tested<br />
Adhesive<br />
Manufacturer<br />
Components<br />
Directions for use<br />
Prime & Bond NT<br />
lot: 0503000835<br />
(P&B)<br />
<strong>Dentsply</strong> DeTrey;<br />
Konstanz, Germany<br />
Conditioner: DeTrey Conditioner (36%<br />
phosphoric acid)<br />
Adhesive: (resin, di- and trimethacrylate,<br />
amorphous functional,<br />
silica, PENTA, cetyl amine<br />
hydrofluoride, acetone, photoinitiators,<br />
stabilizers)<br />
Composite: Esthet·X (microhybrid)<br />
Etch the cavity for 15 s, wash and dry but do<br />
not desiccate. Apply the adhesive and wait<br />
for 20 s. Dry and polymerize for 10 s. Apply<br />
composite and polymerize for 20 s.<br />
XP Bond<br />
lot: 0503004020<br />
(XPB)<br />
<strong>Dentsply</strong>, DeTrey;<br />
Konstanz, Germany<br />
Conditioner: DeTrey Conditioner (36%<br />
phosphoric acid)<br />
Adhesive: tertiary butanol, HEMA,<br />
PENTA, TCB, UDMA, TEG-DMA;<br />
butylated benzenediol, ethyl-4-<br />
dimethylaminobenzoate, camphoroquinone,<br />
nanofillers<br />
Composite: Ceram·X mono (nano<br />
ceramic)<br />
Etch the cavity for 15 s, wash and dry but do<br />
not desiccate. Apply adhesive and wait for<br />
20 s. Dry and polymerize for 10 s. Apply<br />
composite and polymerize for 20 s.<br />
Adper ScotchBond 1 XT<br />
lot: 177215<br />
(SBX)<br />
3M; St Paul, MN, USA<br />
Conditioner: etchant (37% phosphoric<br />
acid)<br />
Adhesive: HEMA<br />
Composite: Filtek Supreme (nano<br />
composite)<br />
Etch cavity for 15 s, wash and dry (do not<br />
desiccate). Apply adhesive and wait for 15 s.<br />
Air dry and light cure for 10 s. Place composite<br />
and light cure for 20 s.<br />
Syntac<br />
lot: G01297<br />
[primer], G04548<br />
[adhesive],<br />
G03430 [bonding]<br />
(SYN)<br />
Ivoclar Vivadent;<br />
Schaan, Liechtenstein<br />
Conditioner: Total Etch (37%<br />
phosphoric acid).<br />
Primer: polyethylene glycol dimethacrylate,<br />
maleic acid, ketone, water<br />
Adhesive: polyethylene glycol<br />
dimethacrylate, glutaraldehyde, water<br />
Bonding: bis-GMA, TEG-MA<br />
Composite: Tretic Evo Ceram<br />
(microhybrid)<br />
Etch cavity for 30 s, wash and dry. Apply<br />
primer, wait for 15 s. Air dry. Apply adhesive<br />
and wait 10 s. Air dry. Apply bonding and air<br />
dry. Light cure for 10 s Place composite and<br />
light cure for 20 s.<br />
Xeno III<br />
lot: 0403001320<br />
[A liquid],<br />
0403001320<br />
[B liquid] (XNO)<br />
<strong>Dentsply</strong>, DeTrey;<br />
Konstanz, Germany<br />
Adhesive: A liquid (HEMA, water,<br />
ethanol, BHT, highly dispersed silicon<br />
dioxide). B liquid (pyro-EMA, PEM-F,<br />
UDMA, BHT, camphoroquinone, ethyl-<br />
4-dimethylaminobenzoate).<br />
Composite: Ceram·X mono (nano<br />
ceramic)<br />
Mix liquid A and B. Apply in the cavity and<br />
wait for 20 s. Dry and polymerize for 10 s.<br />
Apply composite and polymerize for 40 s.<br />
i-Bond<br />
lot: 010082<br />
(IBO)<br />
Heraeus Kulzer;<br />
Hanau, Germany<br />
Adhesive: acetone, water,<br />
methacrylate resins, glutaraldehyde<br />
Composite: Venus (microhybrid)<br />
Apply a copious amount to the cavity. Apply<br />
two additional coats. Wait for 30 s. Dry and<br />
polymerize for 20 s. Apply composite and<br />
polymerize for 20 s.<br />
Clearfil SE Bond<br />
lot: 00453A<br />
[primer]; 00623A<br />
[adhesive]<br />
(CLF)<br />
Kuraray;<br />
Okayama, Japan<br />
Primer: MDP, HEMA, hydrophilic<br />
dimethacrylate, di-camphorquinone,<br />
N,N-diethanol-p-toluidine, water<br />
Bonding: MDP, bis-GMA, HEMA,<br />
hydrophobic dimethacrylate, di-camphoroquinone,<br />
N,N-diethanol-ptoluidine,<br />
silanated colloidal silica<br />
Composite: Clearfil AP X (microhybrid)<br />
Apply primer; wait for 20 s. Dry with mild air<br />
flow. Apply bond. Air flow gently. Light cure<br />
for 10 s, place composite and polymerize for<br />
40 s.<br />
HEMA: 2-hydroxyethylmethacrylate; PENTA: dipentaerythriol penta acrylate monophosphate; TCB: carboxylic acid modified dimethacrylate; TEG-DMA: triethyleneglycol<br />
dimethacrylate; pyro-EMA: phosphoric acid modified methacrylate; PEM-F: monofluorophosphazene-modified methacrylate; MDP: 10-<br />
methacryloyloxydecyl dihydrogen phosphate; UDMA: urethane dimethacrylate; bis-GMA: bis-phenol A diglycidyl methacrylate.<br />
256 The Journal of Adhesive Dentistry
Rosales-Leal<br />
Fig 1 Percentage of cases with each<br />
microlekage grade on the occlusal wall<br />
(O) and on the gingival wall (G) after<br />
24-h water immersion (24 h) and<br />
4000 cycles of thermocycling (4000<br />
c). Columns with the same letter are<br />
statistically similar (p > 0.05).<br />
bevel) were prepared with diamond-coated #330 burs at<br />
high speed under water cooling. Cavities were filled following<br />
manufacturer’s directions for use. The filling material<br />
was placed in two increments. The LED unit SmartLite PS<br />
(<strong>Dentsply</strong> DeTrey; Konstanz, Germany) (light output: 830<br />
mW/cm 2 ) was used for polymerization. The restoration was<br />
finished and polished with abrasive disks. Restored teeth<br />
were divided into two subgroups. In one group, teeth were<br />
kept in water at 37°C for 24 h. In the other group, teeth were<br />
thermocycled 4000 times between water baths at 5°C and<br />
55°C with a dwell time in each bath of 30 s. After sealing the<br />
roots with IRM (<strong>Dentsply</strong> DeTrey), the teeth were covered with<br />
two coats of nail varnish, leaving a 1-mm varnish-free margin<br />
around the restoration. Specimens were then immersed<br />
in a 0.5% water solution of basic fuchsin for 24 h and rinsed<br />
for 5 min with water. After this, specimens were embedded<br />
in acrylic resin, and 3 buccolingual slices of 1 mm thickness<br />
were obtained from each specimen (15 slices resulting in 30<br />
margins in dentin and enamel, per adhesive and aging condition).<br />
Slices were coded and randomly examined independently<br />
under the microscope in a blinded fashion. The<br />
grade of microleakage at occlusal and gingival walls was categorized<br />
as follows: 0: hermetic seal, no leakage; 1: mild microleakage,<br />
dye on no more than half of the wall; 2: moderate<br />
microleakage, dye on more than half of the wall but not<br />
including the axial wall; 3: massive microleakage, dye on the<br />
entire wall, including the axial wall. Data obtained represent<br />
the percentage of each leakage score in all the analyzed<br />
slices. Dentin permeability was evaluated as negative (absence<br />
of dye solution in dentin tissue) or positive (presence<br />
of dye solution in dentin tissue). Microleakage analysis was<br />
performed with the nonparametric Kruskal-Wallis H-test and<br />
Mann-Whitney U-test (p < 0.05). Fisher’s Exact test was used<br />
to evaluate dentin permeability (p < 0.05).<br />
RESULTS<br />
Figures 1 and 2 show the microleakage and dentin permeability<br />
data. The occlusal wall exhibited less leakage than the<br />
gingival wall. Etch-and-rinse adhesives achieved hermetic<br />
occlusal sealing, while self-etching adhesives showed slight<br />
occlusal leakage. Occlusal dentin permeability was negative<br />
for all the adhesives tested. Thermocycling did not affect the<br />
occlusal sealing.<br />
On the gingival wall, XNO and CLF obtained the lowest<br />
leakage, followed by XPB, SBX, and P&B, while SYN and IBO<br />
showed the highest leakage. Thermocycling did not affect<br />
marginal seal in dentin for XPB and SBX, with the latter<br />
showing more leakage after thermocycling compared to<br />
XPB. However, marginal seal of P&B, SYN, XNO, IBO, and CLF<br />
was influenced by thermocycling. Dentin permeability was<br />
negative for XPB, XNO, IBO and CLF. Positive dentin permeability<br />
was observed when P&B, SBX or SYN were used. Thermocycling<br />
increased the dentin positive permeability of P&B<br />
and SYN groups.<br />
DISCUSSION<br />
This in-vitro test provoked microleakage for all adhesives<br />
used. Three main factors could affect the sealing. One factor<br />
is the composite polymerization shrinkage that induces<br />
stress at the bonding interface. 8 This stress can potentially<br />
Vol 9, Supplement 2, 2007 257
Rosales-Leal<br />
Fig 2 Percentage of cases with positive<br />
and negative permeability on the<br />
occlusal wall (O) and on the gingival<br />
wall (G) after 24-h water immersion<br />
(24 h) and 4000 cycles of thermocycling<br />
(4000 c). Columns with the<br />
same letter are statistically similar (p<br />
> 0.05).<br />
break the bond and facilitate leakage. 13,19 Another factor is<br />
that the substrate is a biological tissue, which makes adhesion<br />
difficult. 15 The third factor is the adhesive itself: the<br />
chemical composition plays an important role in achieving a<br />
strong, durable, and biologically compatible bond. 11<br />
Etch-and-rinse adhesives obtained hermetic sealing on<br />
the occlusal wall, which is surrounded by enamel. Enamel is<br />
mainly composed of minerals with no significant amount of<br />
organic compounds or water. 15 Use of phosphoric acid leads<br />
to pronounced etching depth. The adhesive covers a highly<br />
irregular mineral surface with no water, creating a hermetic<br />
and strong bond. 2,6,9,10,13 In contrast, self-etching adhesives<br />
exhibited slight leakage. In general, the pH of acidic<br />
primers is higher than that of phosphoric acid, resulting in a<br />
less pronounced etching effect. 4,21 The consequence in this<br />
in vitro study was a weaker bond with slight leakage. 6,8,15<br />
In agreement with other studies, 6,8,10,13,14 sealing was<br />
better along occlusal than gingival margins. The gingival wall<br />
is formed by dentin, which consists of minerals, organic<br />
compounds (mainly collagen fibers), and water. 15 In addition,<br />
dentin tubules cross the tissue and are full of water. After<br />
phosphoric acid treatment, there is a deep demineralization<br />
front in which the collagen network is exposed, dentin<br />
tubules are opened, and water content is increased. 17 Etchand-rinse<br />
primers have to infiltrate the exposed collagen, replace<br />
the water, and seal the tubules. Therefore, sealing is<br />
complicated, and this histological finding explains the higher<br />
leakage and positive permeability when etch-and-rinse adhesives<br />
are used. XPB was the best etch-and-rinse adhesive<br />
in this study, and always sealed the dentin tubules. This adhesive<br />
uses tertiary butanol as a solvent and provides an increase<br />
in resin content. After polymerization, the bonding<br />
layer will be thicker and consist of a dense polymer matrix<br />
that promotes better sealing.<br />
Self-etching adhesives (except IBO) obtained higher<br />
dentin sealing capability than etch-and-rinse adhesives. To<br />
etch and infiltrate at the same time assures proper covering<br />
of the demineralized dentin and avoids the problem of water,<br />
which etch-and-rinse adhesives have after phosphoric<br />
etching. 4,11 The lower primer acidity promotes less tubule<br />
opening, 14 and then tubule sealing was demonstrated to be<br />
easier. 6 The consequence is that self-etching adhesives always<br />
sealed the dentin tubules and yielded lower leakage<br />
than etch-and-rinse adhesives. In accordance with others,<br />
6,15 IBO allowed more leakage than other adhesives tested.<br />
Despite the higher leakage, IBO sealed always the dentin<br />
tubules.<br />
Evaluation of the dentin permeability to the dye solution<br />
shows the adhesive ability to seal the dentin tubules. 16 Within<br />
the limits of a microleakage study (not being a nanoleakage<br />
evaluation), it can be concluded that if there is leakage<br />
but no positive permeability, the interface failure will be located<br />
over the intact dentin. In this situation, penetrating<br />
bacteria will be surrounded by resin interfaces which could<br />
slow down secondary caries development. In fact, pulp inflammation<br />
was measured in vivo, 12 and when the bacteria<br />
progressed between the cavity and the composite, a low level<br />
of pulp inflammation was found. However, if the bacteria<br />
progress into the dentin tubules, the inflammatory activity is<br />
higher. 3 Therefore, it is desirable to achieve sealing of dentinal<br />
tubules.<br />
Thermocycling is an easy method to age restorations and<br />
results in the highest clinically relevant stress. 3,18 As was<br />
demonstrated in others studies, 18 thermocycling did not af-<br />
258 The Journal of Adhesive Dentistry
Rosales-Leal<br />
fect the occlusal sealing and showed that the enamel junction<br />
is resistant to aging, due to the mineral nature of the tissue<br />
which ensures a better and more durable bond. 4 In contrast,<br />
the dentin bond was susceptible to damage and the<br />
sealing was reduced after thermocycling. 18 The larger proportion<br />
of organic compounds and water in the dentin<br />
makes the union weaker for all the adhesives tested, which<br />
would explain aging. 11,17 Thermocycling accelerates the aging<br />
by hydrolytic degradation of the hydrophilic components<br />
in the bonding system. 12,22 In addition, repetitive contraction/expansion<br />
stress at the bonding interface may lead to<br />
cracks that propagate along the interface and cause in- and<br />
outflow of fluids. 5 When considering distribution of microleakage<br />
grades in all obtained slices, only XPB was not<br />
affected by thermocycling.<br />
Clinically, when a cavity is surrounded by enamel, the<br />
phosphoric acid will ensure a hermetic and durable bond.<br />
When the cavity margins are in dentin, improvements are<br />
necessary, but there are some self-etching adhesives (XNO,<br />
CLF) or etch-and-rinse adhesives (XPB) that obtain excellent<br />
results with no positive dentin permeability and low leakage.<br />
Perhaps more acidic primers could improve the sealing of<br />
composite resin restorations.<br />
CONLUSIONS<br />
In enamel, no microleakage was found when phosphoric<br />
acid was used, but self-etching adhesives showed slight<br />
leakage. The gingival sealing was inferior to the occlusal<br />
sealing. XNO and CLF obtained the best gingival sealing, followed<br />
by XPB, SBX, P&B, and IBO, with SYN demonstrating<br />
the worst sealing. Self-etching adhesives and XPB were able<br />
to hermetically seal the dentin tubules (negative permeability).<br />
Thermocycling did not affect the occlusal bonding or XPB<br />
gingival sealing.<br />
ACKNOWLEDGMENTS<br />
This research was sponsored by <strong>Dentsply</strong> DeTrey, Konstanz, Germany.<br />
3. De Munck J, Vargas M, Iracki J, Van Landuyt K, Poitevin A, Lambrechts P,<br />
Van Meerbeek B. One day bonding effectiveness of new self-etch adhesives<br />
to bur-cut enamel and dentin. Oper Dent 2005;30:39-49.<br />
4. Frankenberger R, Krämer N, Petschelt A. Long-term effect of dentin<br />
primers on enamel bond strength and marginal adaptation. Oper Dent<br />
2000;25:11-19.<br />
5. Gale MS, Darvell BW. Thermal cycling procedures for laboratory testing of<br />
dental restorations. J Dent 1999;27:89-99.<br />
6. Gueders AM, Charpentier JF, Alber AI, Geerts SO. Microleakage after thermocycling<br />
of 4 etch and rinse and 3 self-etching adhesives with and without<br />
flowable composite lining. Oper Dent 2006;31:450-455.<br />
7. Hilton TJ. Can modern procedures and materials reliably seal cavities. In<br />
vitro investigations. Part I. Am J Dent 2002;15:198-210.<br />
8. Kleverlaan CJ, Feilzer AJ. Polymerization shrinkage and contraction stress<br />
of dental composites. Dent Mater 2005;21:1150-1157.<br />
9. Koliniotou-Koumpia E, Dionysiopoulos P, Koumpia E. In vivo evaluation of<br />
microleakage from composites with new dentin adhesives. J Oral Rehabil<br />
2004;31:1014-1022.<br />
10. Manhart J, Chen HY, Mehl A, Weber K, Hickel R. Marginal quality and microleakage<br />
of adhesive class V restorations. J Dent 2001;29:123-130.<br />
11. Mjör IA, Shen C, Eliasson ST, Richter S. Placement and replacement of<br />
restorations in general dental practice in Iceland. Oper Dent 2002;<br />
27:117–123.<br />
12. Murray PE, Hafez AA, Smith AJ, Cox CF. Bacterial microleakage and pulp inflammation<br />
associated with various restorative materials. Dent Mater<br />
2002;18:470-8.<br />
13. Nakabayashi N, Pashley DH. Hybridization of dental hard tissues. Tokio:<br />
Quintessence 1998.<br />
14. Oliveira SSA, Marshall SJ, Hilton JF, Marshall GW. Etching kinetics of a selfetching<br />
primer. Biomaterials 2002;23:4105-4112.<br />
15. Owens BM, Johnson WW. Effecto of insertion technique and adhesive system<br />
on microleakage of Class V resin composite restorations. J Adhes Dent<br />
2005;7:303-308.<br />
16. Rosales-Leal JI, de la Torre-Moreno FJ, Bravo M. Effect of pulp pressure on<br />
the micropermeability and sealing ability of etch&rinse and self-etching adhesives.<br />
Oper Dent 2006; in press.<br />
17. Salz U, Zimmermman J, Zeuner F, Moszner N. Hydrolitic stability of selfetching<br />
adhesive systems. J Adhes Dent 2005;7:107-116.<br />
18. Schuckar M, Geurtsen W. Proximo-cervical adaptation of class II-compoite<br />
restorations after thermocycling: a quantitative and qualitative study. J<br />
Oral Rehabil 1997;24:766-775.<br />
19. Tay FH, Pashley DH. Aggressiveness of contemporary self-etching systems:<br />
I: Depth of penetration beyond dentin smear layers. Dent Mater 2001;<br />
17:296-308.<br />
20. Van Meerbeek B, InokoshiS, Braem M, Lambrechts P, Vanherle G. Morphological<br />
aspects of the resin-dentin interdiffusion zone with different dentin<br />
adhesive systems. J Dent Res 1992;71:1530-1540.<br />
21. Van Meerbeek B, Perdigão J, Lambrechts P, Vanherle G. The clinical performance<br />
of adhesives. J Dent 1998;26:1-20.<br />
22. Yang B, Adlung R, Ludwig K, Böbmann K, Pashley DH, Kern M. Effect of<br />
structural change of collagen fibrils on the durability of dentin boning. Biomaterials<br />
2005;26:5021-5031.<br />
REFERENCES<br />
1. de la Torre-Moreno FJ, Rosales-Leal JI, Bravo M. Effect of cooled composite<br />
inserts in the sealing ability of composite resin restorations placed at intraoral<br />
temperatures: an in vitro study. Oper Dent 2003;28:297-302.<br />
2. De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem<br />
M, Van Meerbeek B. A Critical Review of the Durability of Adhesion to Tooth<br />
Tissue: Methods and Results. J Dent Res 2005;84:118-132.<br />
Clinical relevance: Phosphoric acid ensures hermetic<br />
and durable union on enamel. Although there are some<br />
excellent adhesives, it is nesessary to improve the<br />
dentin sealing.<br />
Vol 9, Supplement 2, 2007 259
Sarrett<br />
260 The Journal of Adhesive Dentistry
Microleakage of XP Bond in Class II Cavities After<br />
Artificial Aging<br />
Jürgen Manhart a /Cordula Trumm b<br />
Purpose: To determine the microleakage of etch and rinse adhesives.<br />
Materials and Methods: Standardized Class II cavities were cut in 40 human molars with one proximal box limited<br />
within enamel and one proximal box extending into dentin. Teeth were assigned randomly to 5 groups (n = 8) and restored<br />
with incrementally placed composite restorations. Five combinations were tested: G1 = XP Bond + CeramX<br />
Mono, G2 = Syntac Classic + Tetric EvoCeram, G3 = Scotchbond 1 XT + Z250, G4 = P&B NT + CeramX Mono, G5 =<br />
Optibond Solo Plus + CeramX Mono. After finishing and polishing, teeth were stored for 48 h in water at 37°C before<br />
being subjected to artificial aging by thermal stress (5/55°C, 2000x, 30 s) and mechanical loading (50 N, 50,000x).<br />
Teeth were isolated with nail varnish and immersed in 5% methylene blue for 1 h. After sectioning, specimens were<br />
evaluated for leakage (ordinal scale: 0 to 4) at enamel and dentin margins under a stereomicroscope. Results were<br />
analyzed using the Kruskal-Wallis H-test and Mann-Whitney U-test (p < 0.05).<br />
Results: Statistical analysis showed significant differences among the groups in both enamel and dentin. Mean<br />
ranks (H-test) were: enamel: G2 (64.44) < G1 (66.69) < G4 (74.88) < G3 (98.25) and G5 (98.25); dentin: G3 (65.53) <<br />
G1 (74.42) < G4 (81.09) < G2 (81.84) < G5 (99.61).<br />
Conclusion: Microleakage of XP Bond is at the same level as or even better than other etch-and-rinse adhesives.<br />
Keywords: Class II restorations, dentin adhesives, composite, microleakage.<br />
J Adhes Dent 2007; 9: 261-264. Submitted for publication: 15.12.06; accepted for publication: 8.1.07.<br />
Despite improvements in the formulation of modern<br />
dentin adhesive systems, the bond strength and marginal<br />
adaptation of composite resins to dentin seems still inferior<br />
and less predictable than adhesion to enamel. 3,11<br />
However, most of the cavities in clinical dentistry, especially<br />
when restorations in the posterior region of the mouth are<br />
replaced, are not limited exclusively within enamel but show<br />
a mixed type configuration with finishing lines in both enamel<br />
and dentin. 3,12 In particular, the adhesive interface between<br />
tooth and restorative material at the gingival finish<br />
line has been recognized as one of the most problematic regions.<br />
5,9 While a great number of self-etching primers and<br />
adhesives have emerged on the market, which are considered<br />
less technique sensitive and less time consuming than<br />
etch-and-rinse adhesives, 13 the latter are still considered<br />
the gold standard with respect to long-term bond strength<br />
and marginal seal, especially for the restoration of highly<br />
loaded Class II cavities or when restorations are bonded to<br />
uninstrumented tooth tissues such as sclerotic dentin in<br />
Class V lesions or virgin enamel in anterior diastema closures.<br />
This study assesses the microleakage of a newly formulated<br />
etch-and-rinse adhesive, based on a tert-butanol solvent<br />
used for the first time, in large Class II cavities after artificial<br />
aging in comparison with well-established competitive<br />
adhesive and composite systems. The null hypothesis tested<br />
was that the type of restorative system used does not significantly<br />
affect the marginal seal.<br />
a Associate Professor, Department of Restorative Dentistry, Ludwig Maximilians<br />
University, Munich, Germany.<br />
b Dentist in Private Practice, Munich, Germany.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Dr. Jürgen Manhart, Department of Restorative Dentistry,<br />
Goethe Street 70, 80336 Munich, Germany. Tel: +49-89-5160-7610, Fax: +49-<br />
89-5160-9302. e-mail: manhart@manhart.com<br />
MATERIALS AND METHODS<br />
Specimen Preparation<br />
Forty freshly extracted caries-free human permanent molars,<br />
stored in a 0.25% mixture of sodium azide in Ringer solution<br />
until the date of use, were used in this in vitro study.<br />
After cleaning the teeth with scalers and polishing with<br />
Vol 9, Supplement 2, 2007 261
Manhart/Trumm<br />
Table 1 Experimental groups and materials used<br />
Group Adhesive Solvent type of Composite<br />
adhesive<br />
G1 XP Bond (<strong>Dentsply</strong> t-butanol Ceram-X Mono (M2)<br />
DeTrey; Konstanz, Germany<br />
(<strong>Dentsply</strong> DeTrey)<br />
G2 Syntac Classic Primer: acetone-water Tetric EvoCeram (A2)<br />
(Ivoclar Vivadent; Adhesive: water (Ivoclar Vivadent)<br />
Schaan, Lichtenstein Heliobond: -<br />
G3 Scotchbond 1 XT Ethanol-water Z250 (A2)<br />
(3M ESPE; Seefeld, Germany) (3M ESPE)<br />
G4 Prime & Bond NT (<strong>Dentsply</strong> Acetone Ceram-X Mono (M2)<br />
DeTrey; Konstanz, Germany<br />
(<strong>Dentsply</strong> DeTrey)<br />
G5 Optibond Solo Plus (Kerr-Hawe; Ethanol Ceram-X Mono (M2)<br />
Bioggio, Switzerland<br />
pumice, standardized Class II inlay cavities (MOD) were prepared,<br />
with one proximal box limited within enamel (1 to 1.5<br />
mm above the cementoenamel junction) and one proximal<br />
box extending into dentin (1 to 1.5 mm below the cementoenamel<br />
junction) (Fig 1). The cavities were 4.0 mm in width<br />
and 3 to 3.5 mm in depth at the occlusal isthmus and 5.0<br />
mm in width at the proximal boxes. The depth of the proximal<br />
boxes in the direction of the axial pulpal walls was 1.5<br />
mm. To achieve divergence angles between opposing walls<br />
of 10 to 12 degrees, cavities were prepared using coarse diamond<br />
burs with a slight taper (855.314, Komet; Lemgo,<br />
Germany) in a high-speed dental handpiece with copious water<br />
spray. Fine grained diamond burs of the same shape<br />
(8855.314, Komet) were used for finishing the preparations.<br />
The internal point and line angles were rounded and enamel<br />
margins were not beveled but prepared in butt-joint configuration.<br />
11 After visual inspection of the cavities for imperfect<br />
finish lines, the 40 prepared teeth were randomly assigned<br />
to 5 experimental groups with 8 teeth each (Table 1),<br />
corresponding to the different restorative techniques. Manufacturers'<br />
instructions for each material were strictly followed.<br />
For the direct composite restorations, all enamel and<br />
dentin surfaces of the cavities were conditioned with 36%<br />
phosphoric acid gel (DeTrey Conditioner 36, <strong>Dentsply</strong> De-<br />
Trey; Konstanz, Germany), starting acid application on enamel,<br />
leaving undisturbed for 15 s, then covering the dentinal<br />
preparation surfaces for an additional 15 s (total-etch technique).<br />
After thoroughly rinsing with water, the cavities were<br />
then gently dried with oil-free compressed air, taking care to<br />
avoid desiccation of the tooth substrate (moist bonding technique).<br />
Following the application and light curing of the adhesive<br />
systems, the cavities were restored with composite<br />
resin (Table 1) using a horizontal and oblique layering technique<br />
with 5 increments in the dentin-limited proximal box<br />
and 4 increments in the enamel-limited box (Fig 1). Each increment<br />
with a maximum thickness of 2 mm was light cured<br />
individually with a LED curing unit (SmartLite PS, <strong>Dentsply</strong><br />
DeTrey) according to the manufacturer’s recommendations.<br />
The light output of the curing unit was monitored at 1065<br />
mW/cm 2 with a calibrated light meter (CureRite, <strong>Dentsply</strong><br />
DeTrey). All restorations were finished and polished immediately<br />
after placement using finishing diamond burs and<br />
polishing disks (Sof-Lex, 3M ESPE; Seefeld, Germany).<br />
Thermocycling and Mechanical Loading<br />
After 48 h storage in distilled water at 37°C, the restored<br />
teeth were subjected to artificial aging by thermocycling and<br />
mechanical loading. All specimens were immersed alternately<br />
in water baths at 5°C and 55°C for 2000 cycles, with<br />
a dwell time of 30 s in each bath and a transfer time of 15<br />
s. Mechanical loading of the teeth, which were mounted on<br />
metallic specimen holders with a light-curing composite, was<br />
conducted in the Munich Oral Environment. 8 The carefully<br />
aligned teeth were loaded in the central fossa of the restorations<br />
in axial direction with a force of 50 N for 50,000 times<br />
at a frequency of 1 Hz. The antagonist material was a Degusit<br />
sphere 6 mm in diameter, which exhibits a hardness<br />
and wear resistance similar to natural enamel. 8,19-21 The<br />
metal specimen holders were mounted on a hard rubber element,<br />
which allowed a sliding movement of the tooth between<br />
the first contact on an inclined plane to the central<br />
fossa. 4 During mechanical loading, the teeth were continuously<br />
immersed in Ringer solution. This oral simulation device<br />
exhibits similar functions to the machine developed by<br />
Krejci. 7<br />
Evaluation of Microleakage<br />
The apices of the artificially aged teeth were sealed with adhesive<br />
and composite (Prime & Bond NT and Ceram-X<br />
Mono). All tooth surfaces were covered with 2 coats of nail<br />
varnish to within approximately 1 mm of the margin of the<br />
restoration. Microleakage was tested using a standardized<br />
dye penetration method. The specimens were immersed in<br />
5% methylene blue at 37°C for 1 hour and then rinsed with<br />
tap water. Teeth were embedded in clear acrylic auto-polymerizing<br />
resin (Technovit, Kulzer; Wehrheim, Germany). All<br />
restorations were sectioned longitudinally with two parallel<br />
cuts in three fragments in mesiodistal direction with a water-cooled<br />
low-speed diamond saw (Varicut, Leco; Kirch-<br />
262 The Journal of Adhesive Dentistry
Manhart/Trumm<br />
heim, Germany), resulting in four readings for each specimen<br />
at the enamel and dentin adhesive interface. An ordinal<br />
scale from 0 to 4 was used to score microleakage separately<br />
at the enamel and dentin margins of each section<br />
(Fig 2). 6 Each section was examined under a stereomicroscope<br />
(Stemi SV 11, Zeiss; Oberkochen Germany) at 40X<br />
magnification and scored by two examiners. Consensus was<br />
forced if disagreements occurred. 16 The results of the microleakage<br />
investigation were analyzed using the nonparametric<br />
Kruskal-Wallis H-test and post-hoc Mann-Whitney<br />
U-test at a significance level of p < 0.05.<br />
RESULTS<br />
Microleakage results are presented in Table 2. The Kruskal-<br />
Wallis H-test revealed statistically significant differences<br />
among the experimental groups in the enamel (p = 0.001)<br />
and dentin margins (p = 0.022) of the Class II restorations.<br />
DISCUSSION<br />
Microleakage studies provide adequate screening methods,<br />
possibly determining what kind of adhesive system will show<br />
acceptable clinical performance. 13 While quantitative marginal<br />
analysis by scanning electron microscopy assesses the<br />
entire circumference of the tooth/restoration interface, it can<br />
only determine the quality of the adhesive interface at the<br />
cavosurface margin. The extension of marginal gaps towards<br />
the axial wall of restorations is commonly assessed by microleakage<br />
studies. 10 Detection of microleakage can be accomplished<br />
with a number of techniques, including bacteria,<br />
chemical or radioactive tracer molecules, fluid permeability,<br />
and dye penetration. 1 The most common technique is the<br />
use of dyes, the penetration of which is determined after sectioning<br />
of the specimen with a magnifying aid.<br />
The type of solvent strongly influences the clinical application<br />
protocol of etch-and-rinse adhesive systems. Acetonebased<br />
systems only work well on a moist dentin surface as<br />
acetone is a water chaser and can lead to rather poor results<br />
on overdried acid-etched dentin surfaces. On the other<br />
Fig 1 Incremental restoration technique and light curing direction.<br />
11<br />
hand, water-based systems are not as sensitive with regard<br />
to dentin moisture content, as they have inherent rewetting<br />
properties, but require a longer evaporation time for the solvent,<br />
because water has a considerably lower vapor pressure<br />
than acetone. 18 If the solvent is not completely evaporated<br />
before light curing the adhesive, flaws can weaken the<br />
hybrid layer, probably causing premature restoration failure. 2<br />
A new type of solvent for adhesives, namely, tert-butanol, was<br />
introduced for XP Bond. Tert-butanol (2-methyl-2-propanol)<br />
Table 2 Microleakage frequency scores at enamel and dentin margins in the experimental groups G1 to G5.<br />
Enamel<br />
Dentin<br />
Leakage 0 1 2 3 4 Mean rank Leakage 0 1 2 3 4 Mean rank<br />
score (Kruskal- score (Kruskal-<br />
Wallis)<br />
Wallis)<br />
G1 28 0 4 0 0 66.69 a G1 20 3 4 5 0 74.4 A<br />
G2 28 3 1 0 0 64.44 a G2 18 1 7 4 2 81.84 A,B<br />
G3 15 7 9 1 0 98.25 b G3 23 5 1 2 1 65.53 A<br />
G4 24 4 4 0 0 74.88 a G4 19 2 2 7 2 81.09 A,B<br />
G5 15 7 9 1 0 98.25 b G5 10 6 7 6 3 99.61 B<br />
Different superscript letters indicate statistically significantly different subsets within each margin segment as determined by post-hoc<br />
multiple comparisons with the Mann-Whitney U-test (p < 0.05)<br />
Vol 9, Supplement 2, 2007 263
Manhart/Trumm<br />
Fig 2 Scoring system for microleakage<br />
evaluation in enamel and dentin.<br />
consists of a C4 body with an alcohol group surrounded by 3<br />
methyl groups, making it totally miscible both with water and<br />
polymerizable resins. Although tert-butanol has a higher molecular<br />
weight than ethanol, the evaporation rate is almost the<br />
same, with a latent heat of vaporization of 41 kJ/mol for tertbutanol<br />
and 42 kJ/mol for ethanol. 15 Vapor pressure of the<br />
different kinds of solvents at 20°C is given as 2330 Pa for water,<br />
4133 Pa for tert-butanol, 5900 Pa for ethanol, and<br />
23,300 Pa for acetone. 14 The properties of tert-butanol make<br />
it possible to use a dappen dish and increase the resin content<br />
of the adhesive, which results in an increase of adhesive<br />
layer thickness and a higher degree of technique robustness<br />
as compared to acetone-based systems. The solvent used for<br />
etch-and-rinse adhesives is a major factor affecting handling<br />
characteristics and performance. 2,17<br />
CONCLUSIONS<br />
The two-step one-bottle tert-butanol-based XP Bond showed<br />
excellent microleakage results in both enamel and dentin,<br />
with the same quality as a well-established three-step etchand-rinse<br />
system.<br />
ACKNOWLEDGEMENTS<br />
This research was sponsored by <strong>Dentsply</strong> DeTrey, Konstanz, Germany<br />
.<br />
REFERENCES<br />
1. Alani AH, Toh CG. Detection of microleakage around dental restorations: a<br />
review. Oper Dent 1997;22:173-185.<br />
2. De Munck J, Van Landuyt K, Peumans M, Poitevin A, Lambrechts P, Braem<br />
M, Van Meerbeek B. A critical review of the durability of adhesion to tooth<br />
tissue: methods and results. J Dent Res 2005;84:118-132.<br />
3. Dietrich T, Lösche AC, Lösche GM, Roulet JF. Marginal adaptation of direct<br />
composite and sandwich restorations in Class II cavities with cervical margins<br />
in dentine. J Dent 1999;27:119-128.<br />
4. Dietschi D, Herzfeld D. In vitro evaluation of marginal and internal adaptation<br />
of class II resin composite restorations after thermal and occlusal<br />
stressing. Eur J Oral Sci 1998;106:1033-1042.<br />
5. Dietschi D, Scampa U, Campanile G, Holz J. Marginal adaptation and seal<br />
of direct and indirect class II composite resin restorations: An in vitro evaluation.<br />
Quintessence Int 1995;26:127-138.<br />
6. Hilton TJ, Ferracane JL. Cavity preparation factors and microleakage of<br />
class II composite restorations filled at intraoral temperatures. Am J Dent<br />
1999;12:123-130.<br />
7. Krejci I, Reich T, Lutz F, Albertoni M. In-vitro-Testverfahren zur Evaluation<br />
dentaler Restaurationssysteme. 1. Computergesteuerter Kausimulator.<br />
Schweiz Monatsschr Zahnmed 1990;100:953-960.<br />
8. Kunzelmann KH. Verschleissanalyse und -quantifizierung von Füllungsmaterialien<br />
in vivo und in vitro. Aachen: Shaker-Verlag 1998.<br />
9. Lutz F, Kull M. The development of a posterior tooth composite system, invitro<br />
investigation. Schweiz Monatsschr Zahnmed 1980;90:455-483.<br />
10. Manhart J, Chen HY, Mehl A, Weber K, Hickel R. Marginal quality and microleakage<br />
of adhesive class V restorations. J Dent 2001;29:123-130.<br />
11. Manhart J, Hollwich B, Mehl A, Kunzelmann KH, Hickel R. Randqualität von<br />
Ormocer- und Kompositfüllungen in Klasse-II-Kavitäten nach künstlicher Alterung.<br />
Dtsch Zahnärztl Z 1999;54:89-95.<br />
12. Mayer R. Ästhetisch-adhäsive Füllungstherapie im Seitenzahngebiet - eine<br />
Illusion Dtsch Zahnärztl Z 1991;46:468-470.<br />
13. Owens BM, Johnson WW, Harris EF. Marginal permeability of self-etch and<br />
total-etch adhesive systems. Oper Dent 2006;31:60-67.<br />
14. Roempps Chemie-Lexikon. 8th Edition, Stuttgart: Franckh-Fachlexikon<br />
1981.<br />
15. Scientific Compendium: XP Bond universal total-etch adhesive. Konstanz:<br />
DENTSPLY DeTrey 2006.<br />
16. Swift EJ, Triolo PT, Barkmeier WW, Bird JL, Bounds SJ. Effect of low-viscosity<br />
resins on the performance of dental adhesives. Am J Dent 1996;9:100-<br />
104.<br />
17. Tay FR, Gwinnett AJ, Wei SHY. Relation between water content in acetone /<br />
alcohol based primer and interfacial ultrastructure. J Dent 1998;26:147-<br />
156.<br />
18. Van Meerbeek B, De Munck J, Yoshida Y, Inoue S, Vargas M, Vijay P, Van<br />
Landuyt K, Lambrechts P, Vanherle G. Adhesion to enamel and dentin: Current<br />
status and future challenges. Oper Dent 2003;28:215-235.<br />
19. Wassell RW, McCabe JF, Walls AWG. Subsurface deformation associated<br />
with hardness measurements of composites. Dent Mater 1992;8:218-<br />
223.<br />
20. Wassell RW, McCabe JF, Walls AWG. A two-body frictional wear test. J Dent<br />
Res 1994;73:1546-1553.<br />
21. Wassell RW, McCabe JF, Walls AWG. Wear characteristics in a two-body<br />
wear test. Dent Mater 1994;10:269-274.<br />
Clinical relevance: The new tert- butanol- based XP<br />
Bond is expected to show good clinical results due to its<br />
chemical composition and technique robustness.<br />
264 The Journal of Adhesive Dentistry
Six-month Clinical Evaluation of XP BOND in Noncarious<br />
Cervical Lesions<br />
Uwe Blunck a /Katharina Knitter b /Klaus-Roland Jahn c<br />
Purpose: To evaluate the 6-month clinical performance of the etch-and-rinse one-bottle adhesive system XP BOND,<br />
used in combination with the composite resin CeramX Duo for the restoration of Class V noncarious cervical lesions<br />
(NCCL).<br />
Materials and Methods: XP BOND was tested in a total of 40 patients who received two Class V CeramX Duo restorations,<br />
Adper Scotchbond 1 XT was used as a control. After cleaning the teeth, the surface of the NCCL was treated<br />
using a carbide bur in dentin and a 40-μm diamond bur in enamel with no retentive preparations. The lesions were<br />
filled with two increments of CeramX Duo after the application of the respective adhesive by a single operator according<br />
to manufacturer’s instructions. After 6 months, the retention and the marginal integrity were evaluated.<br />
Results: Thirty-eight of 40 patients were evaluated after 6 months by two clinicians according to modified USPHS criteria,<br />
and all restorations using XP BOND were still in place. In the control group (using Adper Scotchbond 1XT), one<br />
restoration was lost. The statistical evaluation (chi 2 test) showed no significant differences in any of the criteria. No<br />
difference of marginal integrity was found between the two adhesive systems.<br />
Conclusion: XP BOND meets the ADA success criteria after 6 months.<br />
Keywords: clinical study, noncarious cervical lesions, Class V restorations, adhesive systems.<br />
J Adhes Dent 2007; 9:265-268. Submitted for publication: 15.12.06x; accepted for publication: 3.1.07.<br />
In operative dentistry, etch-and-rinse systems form an important<br />
group of bonding agents that are clinically widely<br />
used. However, as these systems require the demineralization<br />
of dentin and the exposure of the embedded collagen<br />
network, numerous concerns regarding drying of the protein<br />
mesh arise. 5,6,8 This is due to the need to rinse and carefully<br />
a Associate Professor, Charité-Universitätsmedizin Berlin, Dental School, Campus<br />
Virchow Clinic, Berlin, Germany.<br />
b Assistant Professor, Charité-Universitätsmedizin Berlin, Dental School, Campus<br />
Virchow Clinic, Berlin, Germany.<br />
c Professor, Charité-Universitätsmedizin Berlin, Dental School, Campus Virchow<br />
Clinic, Berlin, Germany.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Dr. Uwe Blunck, Charité-Universitätsmedizin Berlin, Dental<br />
School, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany.<br />
Tel: +49-30-450-562-673, Fax: +49-30-450-562-961. e-mail:<br />
uwe.blunck@charite.de<br />
dry the surface after acid etching, in order to enable the constituents<br />
of the bonding system, specifically the uncured<br />
monomers, to penetrate the outer layers of the prepared<br />
dentin. It has therefore been proposed that a bonding system<br />
capable of penetrating dry and collapsed demineralized<br />
dentin would improve bonding, resulting in better clinical<br />
performance. 8<br />
XP BOND is a new one-bottle etch-and-rinse adhesive,<br />
composed of a pre-mixed solution of monomers dissolved in<br />
tert-butanol. Due to an improved ability to diffuse through<br />
partially collapsed demineralized dentin, it is claimed to be<br />
less technique sensitive. 2<br />
As for any other new dental restorative, data from clinical<br />
investigations are crucial to assess the effectiveness and reliability<br />
of the product before being launched. This is needed<br />
in order to validate results from the in vitro studies. As<br />
generally accepted for investigating the clinical effectiveness<br />
of such adhesive systems, noncarious Class V restorations<br />
are the standard test. 9,13 This is due to the fact that<br />
they do not provide any macromechanical retention, they require<br />
at least 50% bonding to dentin, and they are widely<br />
Vol 9, Supplement 2, 2007 265
Blunck et al<br />
Table 1 Materials used in the study<br />
Material Manufacturer Batch No/expiration date<br />
XP BOND <strong>Dentsply</strong> 0512004001/2006-07<br />
(K-0127.04)<br />
Adper 3M ESPE 214747/2007-04<br />
Scotchbond<br />
1 XT<br />
Ceram•X Duo <strong>Dentsply</strong> D1: 0119<br />
D2: 1617<br />
D3: 0174<br />
D4: 0116<br />
DB: 1381<br />
E1: 0583<br />
E2: 2507<br />
E3: 2624<br />
2008-03<br />
seen. Adper Scotchbond 1 XT was applied as recommended<br />
for 15 s in 2 or 3 layers, then carefully dried for at least 5<br />
s, resulting in a glossy surface. Both adhesives were light<br />
cured for 10 s (Smartlite PS, <strong>Dentsply</strong> DeTrey) before the application<br />
of CeramX Duo in at least two increments (depending<br />
on the extension of the cervical lesion); each increment<br />
was light cured for 40 s. The restorations were then finished<br />
and polished by using the PoGo (<strong>Dentsply</strong> DeTrey) polishing<br />
system.<br />
The patients were recalled after 3 and 6 months. The<br />
restorations were checked by two evaluators. The criteria of<br />
interest were retention, postoperative sensitivity, marginal<br />
discoloration, margin integrity, secondary caries, and contour,<br />
using the modified USPHS criteria. 1,17 A vitality test was<br />
performed and the color match of the restoration with the<br />
surrounding tooth structure was also evaluated by the patients.<br />
RESULTS<br />
available, usually found in anterior teeth or premolars with<br />
good access for easy restoring and evaluation.<br />
The purpose of this investigation was to evaluate the effectiveness<br />
of XP BOND compared to Adper Scotchbond 1<br />
XT when used to restore noncarious cervical lesions, both<br />
materials being applied with the etch-and-rinse technique.<br />
MATERIALS AND METHODS<br />
In 40 patients bearing noncarious cervical lesions (NCCL),<br />
80 Class V restorations were placed with either XP BOND or<br />
Adper Scotchbond 1 XT (Table 1). Both agents were used according<br />
to manufacturer’s instructions, combined with the<br />
composite resin CeramX Duo, and completed by a single operator.<br />
The patients (age range 24 to 77, 17 females and 23<br />
males) were all treated within the framework of the student<br />
courses of the Charité Dental School in Berlin, Campus Virchow<br />
Clinic. The reasons for treatment were esthetic considerations,<br />
hypersensitive cervical dentin, or prevention of<br />
further erosion. The agreement for voluntary participation<br />
and informed consent were obtained prior to treatment. Approval<br />
for this study was given by the Ethics Committee of the<br />
Charité Berlin (EA2/230/05, Protocol-Nr.: 14.1165).<br />
Each lesion was initially cleaned with a nonfluoridated<br />
polishing paste (Pellex, KerrHawe; Bioggio, Switzerland) on<br />
a slowly rotating rubber cup, washed, and slightly dried. The<br />
dentin surface was treated using a carbide bur (air cooled)<br />
and the enamel margins were trimmed with a 40-μm diamond<br />
bur under water spray. Saliva control was maintained<br />
by cotton rolls. For both adhesive systems, 36% phosphoric<br />
acid (DeTrey Conditioner 36, <strong>Dentsply</strong> DeTrey; Konstanz,<br />
Germany) was used for standard etching (30 s on enamel<br />
and then 15 s on dentin). After rinsing for at least 15 s, the<br />
cavity was carefully dried without desiccating the dentin. A<br />
single layer of XP BOND was applied for 20 s and the solvent<br />
was evaporated for at least 5 s until a glossy surface was<br />
As seen from the results listed in Table 2, 6 months after<br />
placement, 38 out of 40 patients were available for recall.<br />
All restored teeth were still in contact with their antagonists<br />
(checked during laterotrusion) with 60% showing active wear<br />
facettes. All restorations placed with XP BOND were still in<br />
place and showed no marginal discoloration, while in the<br />
control group, one restoration was lost and two (5.4%)<br />
showed discoloration of less than 50% of the margin length.<br />
In neither group were visible margin irregularities found, and<br />
the margins were not detectable with a dental probe. No secondary<br />
caries and no surface staining were noted. With XP<br />
Bond, one restored tooth showed postoperative hypersensitivity<br />
after 6 months, while in the control group, two teeth<br />
were hypersensitive.<br />
Chi 2 tests were performed using the SPSS (SPSS 12.0 for<br />
Windows, SPSS; München, Germany) statistical package.<br />
We found no significant differences for the different criteria<br />
between the test XP BOND and the control adhesive.<br />
DISCUSSION<br />
Within the limitations of a 6-month clinical study, our data<br />
clearly show the favorable results for XP BOND. The retention<br />
of all restorations of the treated NCCLs and the lack of staining<br />
at the margins, combined with ease of use, show much<br />
promise for similar and other types of restorations as well.<br />
This study, performed in accordance with manufacturer’s instructions,<br />
did not attempt to test this product under extreme<br />
desiccation conditions, for which it is presumed to<br />
have an advantage. 2 Rather, our work was used to assess<br />
the clinical performance of XP BOND under “normal”, reasonable<br />
clinical conditions.<br />
This study was designed to test XP BOND under a rather<br />
well-defined clinical challenge: the treatment of NCCLs.<br />
Class V restorations, used to treat this type of lesion, are a<br />
reasonable choice for a clinical evaluation of a new adhesive<br />
system because the bonding efficacy and handling characteristics<br />
are exposed to a realistic and trying intraoral situa-<br />
266 The Journal of Adhesive Dentistry
Blunck et al<br />
Table 2 Results of the clinical assessment in% of the modified USPH criteria<br />
Criteria for XP BOND [%] Adper Scotchbond 1XT [%]<br />
evaluated<br />
restorations n alpha bravo charlie delta n alpha bravo charlie delta<br />
Retention 38 100 0 0 0 38 97.4 0 0 2.6<br />
Postoperative 38 97.4 2.6 0 0 37 94.6 5.4 0 0<br />
sensitivity (∑)<br />
Marginal 38 100 0 0 0 37 94.6 5.4 0 0<br />
discoloration<br />
Marginal 38 100 0 0 0 37 100 0 0 0<br />
integrity<br />
Secondary 38 100 0 0 0 37 100 0 0 0<br />
caries<br />
Restoration 38 100 0 0 0 37 100 0 0 0<br />
contour<br />
Vitality test 38 100 0 0 0 37 100 0 0 0<br />
tion. A variety of factors, such as the nutrition of the patient,<br />
parafunction, chewing habits, oral hygiene etc, modify the<br />
dentin surface such that the morphology and microstructure<br />
are different compared to surfaces that are exposed during<br />
cavity preparation. 12 Thus, tubules of cervical dentin are exposed<br />
to the oral environment for a longer period and are frequently<br />
partially or totally occluded with precipitates. This<br />
forms a hypermineralized dentin layer that has been found<br />
to be more resistant to etching. 4,10 As a result, a thinner hybrid<br />
layer is formed on the surface, which is different from<br />
the situation in noncervical, cut dentin. 12 It has been shown<br />
that the etch-and-rinse technique results in higher bond<br />
strengths than self-etching adhesive systems. 11 However,<br />
etching dentin with phosphoric acid involves a sensitive<br />
step, namely, the careful drying of the exposed collagen network.<br />
5 This network has to be penetrated completely when<br />
the adhesive system is applied. The results of this study suggest<br />
that XP BOND can produce an effective bond, which is<br />
reflected by the lack of discoloration and the retention results,<br />
as judged by two experienced dentists who have considerable<br />
experience with similar, previous clinical studies.<br />
An additional advantage of the use of a model based on<br />
the treatment of NCCLs is that Class V restorations minimize<br />
the influence of the operator variability. They also simplify<br />
the evaluation procedure of margin integrity, owing to the direct<br />
accessibility during the study period. 9,13 We note, however,<br />
that the margins of Class V restorations cover both<br />
enamel and dentin, and this might increase the retention<br />
due to bonding to the acid-etched enamel. Consequently,<br />
failure might develop due to reduced adhesion to dentin,<br />
which is less suited to withstand mechanical stress during<br />
mastication. Our evaluation of marginal staining and probing<br />
as well as the evaluation of hypersensitivity was aimed<br />
at identifying failures of this type; none were found.<br />
This evaluation is one part of a multicenter study. At present,<br />
the results after 6 months of an identical in vivo study<br />
at the University of Bologna, with 30 patients are available.<br />
The criteria retention, marginal discoloration, margin integrity,<br />
secondary caries, and restoration contour (Table 3)<br />
were all highly rated (alpha USPHS rating) for restorations in<br />
the XP BOND group, where only one restoration (3.3%) exhibited<br />
postoperative sensitivity. In the group using Adper<br />
Scotchbond 1 XT, all criteria received a 100% alpha rating,<br />
with postoperative sensitivity occurring in 7 teeth (23.3%)<br />
with a bravo USPHS rating.<br />
CONCLUSION<br />
It should be borne in mind that these results are preliminary.<br />
Further studies, which are to include other cavity designs<br />
and longer observation periods, can only help to establish<br />
the long-term reliability and the effect on the margin integrity<br />
of the oral environment. However, from the present study,<br />
it can be concluded that the results for the one-bottle etchand-rinse<br />
adhesive system XP BOND meet the criteria for a<br />
provisional acceptance according to ADA guidelines, with<br />
less than 5% failure rate after 6 months of clinical performance.<br />
ACKNOWLEDGMENTS<br />
This study was funded by <strong>Dentsply</strong> DeTrey, Konstanz, Germany.<br />
Vol 9, Supplement 2, 2007 267
Blunck et al<br />
Table 3 Reference data obtained from the clinical assessment in % of the modified USPH criteria from the study center,<br />
Bologna<br />
Criteria for XP BOND [%] Adper Scotchbond 1XT [%]<br />
evaluated<br />
restorations n alpha bravo charlie delta n alpha bravo charlie delta<br />
Retention 30 100 0 0 0 30 100 0 0 0<br />
Postoperative<br />
sensitivity (∑) 30 96.7 3.3 0 0 30 76.7 23.3 0 0<br />
Marginal 30 100 0 0 0 30 100 0 0 0<br />
discoloration<br />
Marginal 30 100 0 0 0 30 100 0 0 0<br />
integrity<br />
Secondary 30 100 0 0 0 30 100 0 0 0<br />
caries<br />
Restoration 30 100 0 0 0 30 100 0 0 0<br />
contour<br />
Vitality test 30 100 0 0 0 30 100 0 0 0<br />
REFERENCES<br />
1. Barnes DM, Blank LW, Gingell JC, Gilner PP. A clinical evaluation of a resinmodified<br />
glass ionomer restorative material. J Am Dent Assoc 1995;<br />
126:1245-1253.<br />
2. <strong>Dentsply</strong> XP BOND for eXtra Performance. Scientific Compendium. Konstanz:<br />
<strong>Dentsply</strong> DeTrey, 2006.<br />
3. Dondi Dall'Orologio G. 6-Month report: clinical evaluation of the adhesive<br />
XP BOND for restoration of cervical lesions at the University of Bologna,<br />
Italy. Report to <strong>Dentsply</strong> 2006.<br />
4. Harnirattisai C, Inokoshi S, Shimada Y, Hosoda H. Adhesive interface between<br />
resin and etched dentin of cervical erosion/abrasion lesions. Oper<br />
Dent 1993;18:138-143.<br />
5. Kanca J. Resin bonding to wet substrate. I. Bonding to dentin. Quintessence<br />
Int 1992;23:39-41.<br />
6. Kanca J. Wet bonding: effect of drying time and distance. Am J Dent<br />
1996; 9:273-276.<br />
7. Loguercio AD, Reis A, Barbosa AN, Roulet JF. Five-year double-blind randomized<br />
clinical evaluation of a resin-modified glass ionomer and a polyacid-modified<br />
resin in noncarious cervical lesions. J Adhes Dent 2003;<br />
5:323-332.<br />
8. Peireira GDS, da, Paulillo LAMS, de Goes MF, Dias CTS. How wet should<br />
dentin be Comparison of methods to remove excess water during moist<br />
bonding. J Adhes Dent 2001;3:257-264.<br />
9. Peumans M, Kanumilli P, De Munck J, Van Landuyt K, Lambrechts P, Van<br />
Meerbeek B. Clinical effectiveness of contemporary adhesives: a systematic<br />
review of current clinical trials. Dent Mater 2005;21:864-881.<br />
10. Sakoolnamarka R, Burrow MF, Prawer S, Tyas MJ. Micromorphological investigation<br />
of noncarious cervical lesions treated with demineralizing<br />
agents. J Adhes Dent 2000;2:279-287.<br />
11. Tay FR, Kwong SM, Itthagarun A, King NM, Yip HK, Moulding KM, Pashley<br />
DH. Bonding of a self-etching primer to non-carious cervical sclerotic<br />
dentin: Interfacial ultrastructure and microtensile bond strength evaluation.<br />
J Adhes Dent 2000;2:9-28.<br />
12. Tay FR, Pashley DH. Resin bonding to cervical sclerotic dentin: a review. J<br />
Dent 2004;32:173-196.<br />
13. Van Meerbeek B, Perdigao J, Lambrechts P, Vanherle G. The clinical performance<br />
of adhesives. J Dent 1998;26:1-20.<br />
268 The Journal of Adhesive Dentistry
Adhesive Luting Revisited: Influence of Adhesive,<br />
Temporary Cement, Cavity Cleaning, and Curing Mode<br />
on Internal Dentin Bond Strength<br />
Roland Frankenberger a /Ulrich Lohbauer b /Michael Taschner c /Anselm Petschelt d /<br />
Sergej A. Nikolaenko e<br />
Purpose: To evaluate microtensile bond strength to Class I cavity floor dentin beneath adhesive inlays that were luted<br />
with different adhesives, temporary cements, cleaning methods, and curing modes.<br />
Materials and Methods: Occlusal cavities (4 x 4 mm, depth 3 mm) were prepared in 96 extracted human third molars.<br />
One part of the cavities was temporized with different temporary cements, which were removed after one week<br />
using three techniques (scaler or air polishing with Prophypearls or ClinPro powder). Direct resin composite inlays<br />
(Clearfil AP-X) were then placed with the luting composite Calibra using three adhesives (XP BOND/SCA, Syntac, Opti-<br />
Bond FL). Teeth were cut into beams and after 24 h of water storage at 37°C, the sticks were subjected to microtensile<br />
bond strength evaluation. Samples were subjected to SEM fractographic analysis of failed interfaces.<br />
Results: Contamination with temporary cement reduced dentin bond strengths (p < 0.05). Removing remnants of cements<br />
with Prophypearls air polishing resulted in the lowest bond strengths (p < 0.05). Separate light curing of the adhesives<br />
did not produce higher dentin bond strengths (p > 0.05). Syntac still worked when Heliobond was omitted (p ><br />
0.05). Immediate dentin sealing prior to temporizing increased internal bond strength (p < 0.05).<br />
Conclusion: The dual-cured adhesive provided higher internal bond strengths between adhesive inlays and dentin. Contamination<br />
of dentin with temporary cements is a hazard for excellent dentin adhesion of adhesive inlays. Therefore, immediate<br />
dentin sealing and resin coating is promising.<br />
Keywords: etch-and-rinse, dentin bonding, adhesive inlays, microtensile bond strength.<br />
J Adhes Dent 2007; 9: 269-273. Submitted for publication: 15.12.06; accepted for publication: 5.1.07.<br />
a Associate Professor, Dental Clinic 1, Operative Dentistry and Periodontology,<br />
University of Erlangen-Nuremberg, Erlangen, Germany.<br />
b Assistant Professor, Dental Clinic 1, Operative Dentistry and Periodontology,<br />
University of Erlangen-Nuremberg, Erlangen, Germany.<br />
c Assistant Professor, Dental Clinic 1, Operative Dentistry and Periodontology,<br />
University of Erlangen-Nuremberg, Erlangen, Germany.<br />
d Professor and Chairman, Dental Clinic 1, Operative Dentistry and Periodontology,<br />
University of Erlangen-Nuremberg, Erlangen, Germany.<br />
e Professor and Head, Department of Operative Dentistry, Krasnojarsk State<br />
Medical Academy, Krasnojarsk, Russia.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Prof. Dr. Roland Frankenberger, Dental Clinic 1, Operative<br />
Dentistry and Periodontology, University of Erlangen-Nuremberg, Glueckstrasse<br />
11, D-91054 Erlangen, Germany. Tel: +49-9131-853-3693, Fax: +49-9131-853-<br />
Adhesive inlays have proven to be durable in the oral cavity.<br />
4,6,15,18,19,24,25,27,28 Clinical reports refer to bulk fractures<br />
as the main failure reason for all ceramic inlay systems.<br />
8-10,15,18,19,26 Clinical trials focusing on ceramic inlays<br />
reveal a certain deterioration of marginal quality; 7 however,<br />
when adhesive inlays are totally bonded to enamel and<br />
dentin, internal dentin bond strength is also an interesting<br />
factor for both stabilization and reduction of postoperative<br />
hypersensitivity. 14,15,20<br />
It is still not fully understood which mode of luting is most<br />
reliable for bonding adhesive tooth-colored inlays to enamel<br />
and dentin, but conventional etch-and-rinse systems with<br />
dual-cured resin composites seem to be the gold standard<br />
for luting. 1,15,18,20,16<br />
Therefore, the aim of the present in vitro study was to evaluate<br />
the performance of different etch-and-rinse adhesives<br />
Vol 9, Supplement 2, 2007 269
Frankenberger et al<br />
Table 1 Overview of materials under investigation<br />
Adhesive +<br />
resin composite<br />
XP BOND/SCA +<br />
Calibra<br />
Syntac<br />
(with Calibra)<br />
OptiBond FL<br />
(with Calibra)<br />
Components<br />
Etchant: 36% phosphoric acid<br />
Primer/Bond: TCB resin, PENTA, UDMA, TEG-DMA, BHT, CQ, functionalized<br />
nanofiller; mixed with SCA (self-curing activator)<br />
Luting composite:<br />
Base: bis-GMA, EBPADM, silica, UDMA, TEG-MA, butylhydoxitoluol, barium<br />
glass, silica<br />
Catalyst: bis-GMA, EBPADM, silica, UDMA, TEG-MA, butylhydoxitoluol, benzoyl<br />
peroxide, barium glass, silica<br />
Etchant: 35% phosphoric acid<br />
Primer: maleic acid 4%, TEG-DMA, water, acetone<br />
Adhesive (2nd primer): water, PEG-DMA, glutaraldehyde<br />
Heliobond: bis-GMA, UDMA, TEG-DMA<br />
Luting composite: see above<br />
Etchant: 37.5% phosphoric acid<br />
Primer: HEMA, GPDM, MMEP, ethanol, water, initiators<br />
Adhesive: bis-GMA, HEMA, GPDM, barium-aluminum borosilicate glass,<br />
disodium hexafluorosilicate, fumed silica (total=48% filler)<br />
Luting composite: see above<br />
Manufacturer<br />
<strong>Dentsply</strong> DeTrey; Konstanz,<br />
Germany<br />
Ivoclar Vivadent; Schaan,<br />
Liechtenstein<br />
Kerr; Orange, CA, USA<br />
for luting of Class I resin composite inlays after different<br />
contaminations, temporary cement removal, and curing<br />
modes. The null hypothesis was twofold, that (1) different<br />
adhesives with different curing modes, and (2) different<br />
temporary cements and cleaning methods would have no<br />
influence on dentin bond strength beneath adhesively luted<br />
inlays.<br />
MATERIALS AND METHODS<br />
Ninety-six intact, noncarious, unrestored human third molars<br />
were stored in an aqueous solution of 0.5% chlora<br />
mine T at 4°C for up to 30 days. The teeth were debrided of<br />
residual plaque and calculus, and examined to ensure that<br />
they were free of defects under a light microscope at 20X<br />
magnification. Standardized Class I cavity preparations (4<br />
mm in width and length, 3 mm in depth) were performed.<br />
Cavities were cut using coarse diamond burs under profuse<br />
water cooling (80 μm, Two-Striper Prep-Set, Premier; St Paul,<br />
MN, USA), and finished with a 25-μm finishing diamond. Inner<br />
angles of the cavities were rounded and the margins<br />
were not bevelled. To guarantee a rectangular relation between<br />
the bonded interface and the direction of the later-cut<br />
μTBS beam, the cusps were flattened by 2 mm and then the<br />
cavity floor was prepared parallel to the flattened cusps.<br />
Direct resin composite inlays (Clearfil AP-X, Kuraray;<br />
Tokyo, Japan) were manufactured under isolation of the cavities<br />
with glycerine gel. The inlays received a cubic shape<br />
with the surface being parallel to the bottom of the cavity to<br />
facilitate positioning of the light-curing tip. The bottom sides<br />
of the inlays were sandblasted with aluminum oxide (Rondoflex<br />
27 μm, KaVo; Biberach, Germany), washed with 70%<br />
ethanol, and dried. The prepared teeth received provisional<br />
restorations (Fermit N, Ivoclar Vivadent; Schaan, Liechtenstein),<br />
and were stored in distilled water at 37°C for one<br />
week. The provisional restorations were either inserted with<br />
or without two different temporary cements (Temp Bond /<br />
Temp Bond NE, Kerr; Orange, CA, USA). Two more groups<br />
with hybridizing dentin prior to temporizing were also made,<br />
either with one coat of adhesive (immediate dentin sealing 17<br />
[IDS]) or with one 0.5-mm layer of flowable resin composite<br />
(X-Flow, <strong>Dentsply</strong> DeTrey; Konstanz, Germany) (resin coating<br />
technique 13 [RC]). Here, temporary cements were omitted<br />
because they play no role in bonding to dentin.<br />
After removing Fermit, cement remnants were removed<br />
with a scaler or using different air-polishing powders (Prophypearls<br />
Powder, KaVo; ClinPro Prophy Powder, 3M ESPE;<br />
Seefeld, Germany), both operating in a Prophyflex air-polishing<br />
device (KaVo) at the level of the occlusal cavity margin<br />
for 10 s. 2 After rinsing with tap water and drying, the cavities<br />
were treated with different adhesives and one luting<br />
composite (Table 1). Internal surfaces of the resin composite<br />
inlays were silanized with Monobond S (Ivoclar Vivadent),<br />
dried, and covered with the respective adhesive, which was<br />
not light cured. Adhesives and luting resin composite were<br />
polymerized with a Translux CL light-curing unit (Heraeus<br />
Kulzer; Dormagen, Germany). The intensity of the light was<br />
checked periodically with a radiometer (Demetron Research;<br />
Danbury, CT, USA) to ensure that 600 mW/cm 2 was always<br />
exceeded during the experiments. Adhesives were light<br />
cured for 40 s in the case where the protocol advised it. Oth-<br />
270 The Journal of Adhesive Dentistry
Frankenberger et al<br />
Table 2 Results of μTBS investigation to cavity floor dentin<br />
Adhesive<br />
Dentin<br />
contamination<br />
Cleaning<br />
method<br />
Curing mode<br />
of adhesive<br />
μTBS<br />
to cavity floor<br />
dentin in MPa (SD)<br />
XP BOND / SCA<br />
---<br />
---<br />
---<br />
---<br />
Temp Bond<br />
Temp Bond<br />
Temp Bond<br />
Temp Bond NE<br />
Temp Bond NE<br />
Temp Bond NE<br />
---<br />
---<br />
---<br />
---<br />
Scaler<br />
Prophypearls<br />
Clinpro powder<br />
Scaler<br />
Prophypearls<br />
Clinpro powder<br />
No LC<br />
separate<br />
IDS<br />
RC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
39.6 (26.6)<br />
36.3 (19.2)<br />
38.4 (13.6)<br />
53.9 (17.1)<br />
21.9 (20.7)<br />
10.0 (14.9)<br />
34.5 (8.1)<br />
27.3 (16.2)<br />
11.0 (14.9)<br />
36.3 (20.5)<br />
Syntac<br />
---<br />
---<br />
---<br />
---<br />
---<br />
Temp Bond<br />
Temp Bond<br />
Temp Bond<br />
Temp Bond NE<br />
Temp Bond NE<br />
Temp Bond NE<br />
---<br />
---<br />
---<br />
---<br />
---<br />
Scaler<br />
Prophypearls<br />
Clinpro powder<br />
Scaler<br />
Prophypearls<br />
Clinpro powder<br />
No LC<br />
separate<br />
IDS<br />
RC<br />
w/o adhesive<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
13.7 (15.7)<br />
19.0 (14.2)<br />
30.1 (15.9)<br />
47.9 (18.0)<br />
22.5 (14.3)<br />
9.7 (8.9)<br />
5.9 (6.5)<br />
12.1 (11.4)<br />
7.1 (10.3)<br />
4.1 (5.1)<br />
12.0 (8.9)<br />
OptiBond FL<br />
---<br />
---<br />
---<br />
---<br />
---<br />
Temp Bond<br />
Temp Bond<br />
Temp Bond<br />
Temp Bond NE<br />
Temp Bond NE<br />
Temp Bond NE<br />
---<br />
---<br />
---<br />
---<br />
---<br />
Scaler<br />
Prophypearls<br />
Clinpro powder<br />
Scaler<br />
Prophypearls<br />
Clinpro powder<br />
No LC<br />
separate<br />
IDS<br />
RC<br />
w/o adhesive<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
no LC<br />
19.2 (16.3)<br />
26.6 (13.8)<br />
37.7 (16.9)<br />
50.7 (17.8)<br />
24.0 (17.5)<br />
10.4 (9.5)<br />
6.5 (6.5)<br />
18.2 (12.6)<br />
8.3 (10.2)<br />
8.2 (10.5)<br />
22.1 (18.0)<br />
IDS=immediate dentin sealing; RC=resin-coating technique<br />
erwise, the luting composites were cured together with the<br />
adhesives with an occlusal curing time of 220 s.<br />
The peripheral areas of the reconstructed/filled teeth<br />
were removed, remaining specimens were sectioned into<br />
slices in an apical direction, which were sectioned again to<br />
yield resin-dentin beams. The saw was adjusted to steps of<br />
1 mm, due to the thickness of the blade (300 μm) resulting<br />
in sticks with a cross-sectional area of 700 x 700 μm (0.5<br />
mm 2 ). From the resulting sticks of each group, 20 were selected<br />
(n = 20). These 20 sticks had to have a remaining<br />
dentin thickness to the pulp of 2.0 ± 0.5 mm. If more than<br />
20 beams were collected with the correct remaining dentin<br />
thickness, 20 sticks were randomly selected. For the case<br />
that one or more of the selected sticks failed due to the sectioning<br />
process, the percentage of prematurely failed specimens<br />
in relation to the total number of selected specimens<br />
was recorded. If more than 20 beams were collected with<br />
the correct remaining dentin thickness, 20 sticks were randomly<br />
selected. For the case that one or more of the selected<br />
sticks failed due to the sectioning process, the failed<br />
specimens received 0 MPa as final μTBS result. 38 The μTBS<br />
sticks were stored in distilled water for 24 h at 37°C and then<br />
fractured according to a well-suited protocol. 3 Fractured interfaces<br />
were submitted to SEM (Leitz ISI 50, Akashi; Tokyo,<br />
Japan; sputtering with Balzers SCD; Balzers, Liechtenstein).<br />
Statistical analysis was performed using SPSS, Version<br />
14.0 for Windows XP (SPSS; Chicago, IL, USA). As the majority<br />
of groups did not exhibit normal data distribution (Kolmogorov-Smirnov<br />
test), nonparametric tests were used<br />
(Wilcoxon matched-pairs signed-ranks test, Mann-Whitney<br />
U-test) for pairwise comparisons at the 95% significance<br />
level.<br />
Vol 9, Supplement 2, 2007 271
Frankenberger et al<br />
Fig 1 Fractured μTBS specimen at the resin composite aspect<br />
with Syntac not separately cured. Short resin tags have been<br />
pulled out of the dentin at the cavity floor.<br />
Fig 2 Fractured μTBS specimen with XP Bond + SCA at the<br />
dentin side. The interface is ruptured at the bottom of the hybrid<br />
layer at the transition to the funnel-shaped orifices of dentinal<br />
tubules.<br />
RESULTS<br />
The results of the study are displayed in Table 2. Contamination<br />
with temporary cement reduced dentin bond<br />
strengths (p < 0.05). Removing remnants of cements with<br />
Prophypearls air-polishing significantly decreased dentin<br />
bond strengths (p < 0.05). Separate light curing of the adhesives<br />
did not produce higher dentin bond strengths (p ><br />
0.05). The dual-cured adhesive exhibited significantly higher<br />
bond strengths in control groups without IDS (p < 0.05).<br />
Immediate dentin sealing (resin coating) prior to temporizing<br />
increased internal bond strength for all adhesives under investigation<br />
(p < 0.05). Fractographic analysis exhibited insufficient<br />
interface formation when light-cured adhesives<br />
were cured together with the luting resin composite (Fig 1).<br />
Fractured interfaces of XP Bond showed characteristic positive<br />
features of typical etch-and-rinse adhesives (Fig 2).<br />
DISCUSSION<br />
The survival of ceramic inlays is fundamentally dependent<br />
on durable enamel bonding; also when the dentin aspects<br />
were covered with a cement lining, long-term success was reported<br />
to be good. 4,14-16 However, the present study exclusively<br />
focussed on internal dentin bond strength beneath adhesive<br />
inlays. Due to easier processing, direct resin composite<br />
inlays were chosen, because they reveal the same<br />
dentin-resin composite interface as ceramic inlays. 12,13,16,29<br />
Hikita et al 11 evaluated enamel and dentin bond<br />
strengths of luting systems for adhesive inlays. It was remarkable<br />
that Syntac and Variolink II without separate light<br />
curing of the adhesive obtained the lowest dentin bond<br />
strengths in that investigation. This may be surprising, because<br />
especially this combination of light-curing adhesive<br />
and dual-curing luting resin composite has been repeatedly<br />
reported to be clinically effective. 4,14,15 This clearly demonstrates<br />
that the clinical success of ceramic inlays as well as<br />
of direct resin composite restorations may be primarily dependent<br />
on good and durable marginal adaptation to enamel.<br />
The present results also clearly confirm the theory that<br />
solely light-cured adhesives do not receive enough light energy<br />
through 3-mm-thick adhesive inlays, not even under laboratory<br />
conditions. To elucidate the problem of insufficient<br />
light curing through ceramic inlays as demonstrated in vitro,<br />
marginal quality assessment alone is not sufficient. A previous<br />
and often cited study with conical ceramic inserts luted<br />
into standardized dentin cavities showed good bond<br />
strengths and marginal adaptation in vitro, even when the<br />
light-curing adhesive was not light cured separately. 5 However,<br />
in the course of push-out investigations, in most of the<br />
cases, enough light energy passes through the specimens,<br />
being considerably thinner than inlay cavities. Previous results<br />
showed that enough light intensity was always transported<br />
to the marginal areas of the luted ceramic inays,<br />
even in proximal margins below the CEJ. 1 Nevertheless, this<br />
does not necessarily mean that the light-curing adhesives<br />
under investigation revealed a complete cure in all areas beneath<br />
the ceramic inlays. The present results clearly show<br />
that results of marginal analyses may produce results which<br />
are not representative for what is happening deeper inside<br />
the restored tooth.<br />
In this context, it has often been discussed in the past<br />
whether a light-cured adhesive has to be separately light<br />
cured prior to the application of a luting resin composite.<br />
This study indicates that a separate light-curing step of lightcured<br />
adhesives was not beneficial for dentin bond strength.<br />
This may be attributed to the fact that heavily air-thinned layers<br />
of bonding agents are subjected to severe oxygen inhibition<br />
and are therefore almost not cured despite the presence<br />
of light energy for 40 s. Finally, due to reasons of contamination<br />
and oxygen inhibition, immediate dentin sealing<br />
272 The Journal of Adhesive Dentistry
Frankenberger et al<br />
or resin coating may be the method of choice to pretreat<br />
dentin surfaces being chosen for adhesive luting, because<br />
contamination with temporary cements is avoided and appropriate<br />
polymerization of the resin-dentin interface is guaranteed.<br />
12,13,17,21,23,29 This is given even more credence, because<br />
the present study was able to demonstrate that any<br />
contamination with temporary cements is crucial, and removal<br />
methods such as air polishing are sometimes disadvantageous,<br />
as proven in a previous investigation conducted<br />
with the effect of air-polishing alone. 2 Finally, both null hypotheses<br />
had to be rejected.<br />
CONCLUSIONS<br />
The dual-cured adhesive provided higher internal bond<br />
strengths to dentin beneath adhesive inlays. Contamination<br />
of dentin with temporary cements is a hazard for excellent<br />
dentin adhesion of adhesive inlays. Therefore, immediate<br />
dentin sealing is promising. Among temporary cement cleaning<br />
techniques, polishing air abrasion with Prophypearls severely<br />
reduces dentin bond strengths.<br />
REFERENCES<br />
1. Frankenberger R, Lohbauer U, Schaible BR, Nikolaenko SA, Naumann M.<br />
Luting of ceramic inlays in vitro: marginal quality of self-etch and etch-andrinse<br />
adhesives vs. self-etch cements. Dent Mater 2006;submitted.<br />
2. Frankenberger R, Lohbauer U, Tay FR, Taschner M, Nikolaenko SA. Air-polishing<br />
powders differently affect dentin bonding. J Adhes Dent 2007;<br />
accepted for publication.<br />
3. Frankenberger R, Pashley DH, Reich SM, Lohbauer U, Petschelt A, Tay FR.<br />
Characterisation of resin-dentine interfaces by compressive cyclic loading.<br />
Biomaterials 2005;26:2043-2052.<br />
4. Frankenberger R, Petschelt A, Krämer N. Leucite-reinforced glass ceramic<br />
inlays and onlays after six years: clinical behavior. Oper Dent<br />
2000;25:459-465.<br />
5. Frankenberger R, Sindel J, Krämer N, Petschelt A. Dentin bond strength<br />
and marginal adaptation: direct composite resins vs ceramic inlays. Oper<br />
Dent 1999;24:147-155.<br />
6. Fuzzi M, Rappelli G. Ceramic inlays: clinical assessment and survival rate.<br />
J Adhes Dent 1999;1:71-79.<br />
7. Hayashi M, Tsubakimoto Y, Takeshige F, Ebisu S. Analysis of longitudinal<br />
marginal deterioration of ceramic inlays. Oper Dent 2004;29:386-391.<br />
8. Hayashi M, Tsuchitani Y, Kawamura Y, Miura M, Takeshige F, Ebisu S. Eightyear<br />
clinical evaluation of fired ceramic inlays. Oper Dent 2000;25:473-<br />
481.<br />
9. Hayashi M, Wilson NH, Yeung CA, Worthington HV. Systematic review of ceramic<br />
inlays. Clin Oral Investig 2003;7:8-19.<br />
10. Hayashi M, Yeung CA. Ceramic inlays for restoring posterior teeth. Aust<br />
Dent J 2004;49:60.<br />
11. Hikita K, Van MB, De MJ, Ikeda T, Van LK, Maida T, Lambrechts P, Peumans<br />
M. Bonding effectiveness of adhesive luting agents to enamel and<br />
dentin. Dent Mater 2006.<br />
12. Islam MR, Takada T, Weerasinghe DS, Uzzaman MA, Foxton RM, Nikaido T,<br />
Tagami J. Effect of resin coating on adhesion of composite crown restoration.<br />
Dent Mater J 2006;25:272-279.<br />
13. Jayasooriya PR, Pereira PN, Nikaido T, Tagami J. Efficacy of a resin coating<br />
on bond strengths of resin cement to dentin. J Esthet Restor Dent<br />
2003;15:105-113.<br />
14. Krämer N, Ebert J, Petschelt A, Frankenberger R. Ceramic inlays bonded<br />
with two adhesives after 4 years. Dent Mater 2006;22:13-21.<br />
15. Krämer N, Frankenberger R. Clinical performance of bonded leucite-reinforced<br />
glass ceramic inlays and onlays after eight years. Dent Mater<br />
2005;21:262-271.<br />
16. Krämer N, Lohbauer U, Frankenberger R. Adhesive luting of indirect<br />
restorations. Am J Dent 2000;13:60D-76D.<br />
17. Magne P, Kim TH, Cascione D, Donovan TE. Immediate dentin sealing improves<br />
bond strength of indirect restorations. J Prosthet Dent 2005;<br />
94:511-519.<br />
18. Manhart J, Chen H, Hamm G, Hickel R. Buonocore Memorial Lecture. Review<br />
of the clinical survival of direct and indirect restorations in posterior<br />
teeth of the permanent dentition. Oper Dent 2004;29:481-508.<br />
19. Martin N, Jedynakiewicz NM. Clinical performance of CEREC ceramic inlays:<br />
a systematic review. Dent Mater 1999;15:54-61.<br />
20. Mehl A, Kunzelmann KH, Folwaczny M, Hickel R. Stabilization effects of<br />
CAD/CAM ceramic restorations in extended MOD cavities. J Adhes Dent<br />
2004;6:239-245.<br />
21. Nikaido T, Cho E, Nakajima M, Tashiro H, Toba S, Burrow MF, Tagami J. Tensile<br />
bond strengths of resin cements to bovine dentin using resin coating.<br />
Am J Dent 2003;16 Spec No:41A-46A.<br />
22. Nikolaenko SA, Lohbauer U, Roggendorf M, Petschelt A, Dasch W, Frankenberger<br />
R. Influence of c-factor and layering technique on microtensile bond<br />
strength to dentin. Dent Mater 2004;20:579-585.<br />
23. Ozturk N, Aykent F. Dentin bond strengths of two ceramic inlay systems<br />
after cementation with three different techniques and one bonding system.<br />
J Prosthet Dent 2003;89:275-281.<br />
24. Pallesen U, van Dijken JW. An 8-year evaluation of sintered ceramic and<br />
glass ceramic inlays processed by the Cerec CAD/CAM system. Eur J Oral<br />
Sci 2000;108:239-246.<br />
25. Posselt A, Kerschbaum T. Longevity of 2328 chairside Cerec inlays and onlays.<br />
Int J Comput Dent 2003;6:231-248.<br />
26. Reiss B. Clinical results of Cerec inlays in a dental practice over a period of<br />
18 years. Int J Comput Dent 2006;9:11-22.<br />
27. Schulz P, Johansson A, Arvidson K. A retrospective study of Mirage ceramic<br />
inlays over up to 9 years. Int J Prosthodont 2003;16:510-514.<br />
28. Sjögren G, Molin M, van Dijken JW. A 10-year prospective evaluation of<br />
CAD/CAM-manufactured (Cerec) ceramic inlays cemented with a chemically<br />
cured or dual-cured resin composite. Int J Prosthodont 2004;17:241-<br />
246.<br />
29. Stavridakis MM, Krejci I, Magne P. Immediate dentin sealing of onlay<br />
preparations: thickness of pre-cured dentin bonding agent and effect of<br />
surface cleaning. Oper Dent 2005;30:747-757.<br />
Clinical relevance: Dual-cured adhesives are beneficial<br />
for adhesive luting. Sealing dentin prior to temporizing<br />
improves dentin bond strength.<br />
Vol 9, Supplement 2, 2007 273
Sarrett<br />
274 The Journal of Adhesive Dentistry
XP BOND in Self-curing Mode used for Luting Porcelain<br />
Restorations. Part A: Microtensile Test<br />
Ornella Raffaelli a /Maria Crysanti Cagidiaco b /Cecilia Goracci c /Marco Ferrari d<br />
Purpose: To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cement used<br />
in different curing modes to lute ceramic disks of different thicknesses.<br />
Materials and Methods: Empress II disks (Ivoclar-Vivadent) were luted to dentin using XP BOND (<strong>Dentsply</strong> [XP]) in<br />
combination with the proprietary self-curing activator (SCA) and cement Calibra (<strong>Dentsply</strong> [C]). Curing of the adhesive<br />
was induced either by mixing with the activator (activator, groups 3 to 6) or by light irradiation for 20 s (group 2). The<br />
cement was either light cured for 40 s through the ceramic onlay (groups 1 to 5) or cured chemically (groups 6 and 7).<br />
Groups 2 and 4 were compared with group 1, in which Prime & Bond NT (<strong>Dentsply</strong> DeTrey) was tested as control. In<br />
groups 3 and 6, 2-mm-thick onlays were luted with XP+SCA, and the cement was light cured for 40 s or let autocure for<br />
5 min, respectively. These groups were compared with group 7, in which Syntac (Ivoclar Vivadent) was applied with C<br />
and, in order to reproduce the handling procedures of group 6 (although contrary to manufacturer’s instructions), no<br />
light irradiation was provided for the adhesive or the cement. The influence of onlay thickness (2, 3, 4 mm) on the<br />
bond strength developed by XP+SCA/C was assessed by comparing groups 3, 4, 5. In these groups, C was light cured<br />
for 40 s through the onlay. Microtensile beams were obtained from the luted teeth.<br />
Results: Bond strengths not including pretest failures (in parentheses: value including pretest failures as 0 MPa) were<br />
21.0 (17.5) MPa in group 1, 24.9 (21.2) MPa in group 2, 23.7 (21.3) MPa in group 3, 29.9 (26.7) MPa in group 4, 30.3<br />
(24.6) MPa in group 5, 28.6 (24.6) MPa in group 6, and 17.1 (9.2) MPa in group 7. Statistically significant differences<br />
were found between groups 1 and 4, groups 3 and 5, and groups 6 and 7.<br />
Conclusion: The bonding potential of XP BOND used with the activator or light cured in combination with Calibra in<br />
self- or dual-curing mode outperformed that of a control adhesive-cement system. The bond strength of XP+ SCA + Calibra<br />
was not negatively affected by the onlay thickness.<br />
J Adhes Dent 2007; 9: 275-278. Submitted for publication: 15.12.06; accepted for publication: 5.1.07.<br />
a PhD Student, Department of Dental Materials and Prosthodontics, University of<br />
Siena, Siena, Italy.<br />
b Clinical Professor of Dentistry, Department of Dental Materials and Prosthodontics,<br />
University of Siena, Siena, Italy.<br />
c Assistant Professor and Chair, Department of Endodontics, University of Siena,<br />
Siena, Italy.<br />
d Professor and Chair, Department of Dental Materials and Prosthodontics, University<br />
of Siena, Siena, Italy.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006.<br />
Reprint requests: Prof. Marco Ferrari, Research Center for Dental Health, 19 Piazza<br />
Attias, 57120 Livorno, Italy. Tel: +39-586-892-283, Fax: +39-586-898-305.<br />
e-mail: ferrarimar@unisi.it<br />
Many new bonding systems are introduced every year on<br />
the market. Some of them are primer-adhesive solutions<br />
in combination with a prior phosphoric acid treatment,<br />
others avoid the total-etch step and offer self-etching or selfadhesive<br />
bonding solutions. 3,5,7-10<br />
However, practitioners would like to use the same bonding<br />
systems for all clinical applications, although most simplified<br />
bonding solutions are not necessarily indicated for<br />
luting indirect restorations, limiting their clinical indications<br />
to direct restorations.<br />
Recently, XP BOND (<strong>Dentsply</strong> DeTrey; Konstanz, Germany),<br />
using tert-butanol for the first time as solvent in dentistry,<br />
was proposed as a one-bottle universal adhesive, also<br />
in combination with a new self-curing activator (SCA).<br />
When luting a porcelain restoration, differences in thickness<br />
may reduce the light penetration, resulting in a reduced<br />
polymerization rate of the luting material. 1,2,4 To avoid<br />
an incomplete cure of the resin cement adhesive interface,<br />
the self-curing activator can be used.<br />
Consequently, the aims of this study were to evaluate (1)<br />
the procedure for adhesively luting ceramic to dentin and,<br />
specifically, when light is applied, to cure either the adhesive<br />
before or after applying the cement, (2) the influence of ceramic<br />
thickness when the adhesive is not separately light<br />
cured but mixed with a self-curing activator (SCA), (3) the influence<br />
of SCA on the bonding efficacy when no light is<br />
used. The null hypothesis tested is that differences in porcelain<br />
thickness and curing mode do not affect the bond<br />
strength values.<br />
Vol 9, Supplement 2, 2007 275
Raffaelli et al<br />
Table 1 Groups of materials and techniques<br />
Groups Adhesive Activator Adhesive Cement Ceramic disk<br />
thickness (mm)<br />
1 Prime & Bond NT no LC DC 3<br />
2 XP BOND no LC DC 3<br />
3 XP BOND yes NC DC 2<br />
4 XP BOND yes NC DC 3<br />
5 XP BOND yes NC DC 4<br />
6 XP BOND yes NC CC 2<br />
7 Syntac* - NC CC 2<br />
NC: not cured (mix with SCA is applied, but not light cured); LC: light cured (light cured before placement); DC: dual curing (Light is applied on the mixed<br />
cement); CC: chemically cured (no light is used at all). *According to the directions for use, application and light curing of Heliobond is mandatory when combined<br />
with self curing materials.<br />
MATERIALS AND METHODS<br />
Bonding was performed on 70 noncarious human third molars<br />
that were extracted after informed consent had been obtained.<br />
They were stored in a 1% chloramine T solution at<br />
4°C and used within one month following extraction. Prior to<br />
the bonding experiments, the teeth were retrieved from the<br />
disinfectant solution and stored in distilled water, with four<br />
changes of the latter within 48 h to remove the disinfectant.<br />
Tooth Preparation – Bonding to Deep Dentin<br />
Bonding was performed on the occlusal surfaces of deep<br />
coronal dentin. The occlusal enamel and the superficial<br />
dentin of each tooth were removed using a slow-speed saw<br />
(Isomet, Buehler; Lake Bluff, IL, USA) under water cooling.<br />
The tooth surfaces were polished with wet 180-grit SiC papers.<br />
The teeth were divided into 7 experimental groups of<br />
10 teeth each. The experimental dentin groups are listed in<br />
Table 1.<br />
Coupling of Processed Ceramic<br />
Empress 2 blocks (shade A2) were reduced with the Isomet<br />
saw under water cooling to produce blocks with dimensions<br />
similar to those of the teeth to be bonded. Each reduced<br />
block was then sectioned with the Isomet saw to produce<br />
2-, 3-, or 4-mm-thick, parallel-sided ceramic onlays. The inner<br />
surface of each ceramic onlay was sandblasted with 50-<br />
μm alumina, etched with a hydrofluoric acid gel for 90 s,<br />
washed, air dried, and silanized using Calibra silane<br />
(<strong>Dentsply</strong>).<br />
To bond the ceramic disks to the dentin surface, the<br />
bonding systems and the resin cement were used following<br />
manufacturer’s instructions. As a curing device, a QTH light<br />
(<strong>Dentsply</strong> DeTrey) was used (power output: 800 mW/cm 2 ).<br />
The intensity of the curing light was tested before and after<br />
curing with a radiometer. The bonded specimens were<br />
stored in distilled water at 37°C for 24 h before further laboratory<br />
processing.<br />
TBS Evaluation and SEM Fractographic Analysis<br />
Each tooth was sectioned occluso-gingivally into serial slabs<br />
using an Isomet saw under water cooling. The two slabs from<br />
each tooth were further sectioned into 0.9 x 0.9 mm ceramic-dentin<br />
beams, according to the technique for the<br />
nontrimming version of the microtensile test. 6 Each group<br />
provided 37 to 53 beams for bond strength evaluation. Premature<br />
failures that occurred during sectioning were recorded.<br />
The specimens were stressed to failure under tension using<br />
a universal testing machine (Model 4440, Instron; Canton,<br />
MA, USA) at a crosshead speed of 1 mm/min. The data<br />
were analyzed using one-way ANOVA and Tukey’s multiple<br />
comparison tests at α = 0.05.<br />
Representative fractured beams from each of the 7<br />
groups were air dried and sputter coated with gold/palladium<br />
for examination with a conventional SEM (Jeol; Tokyo,<br />
Japan).<br />
Statistical Analysis<br />
Three different one-way ANOVAs were performed, each involving<br />
different groups (Tables 2 to 4). The first two analyses<br />
were performed in the groups with 3-mm and 2-mm ceramic<br />
disks, respectively. The last analysis was performed<br />
on groups with 3 different ceramic thicknesses (2, 3, and 4<br />
mm) when samples were luted with XP+SCA+Calibra DC.<br />
Premature failures were excluded from the statistical analysis.<br />
It was also verified that the tooth of origin was not a significant<br />
factor for bond strength.<br />
As the bond strength data were normally distributed (Kolmogorov-Smirnov<br />
test) and groups had homogeneous variances<br />
(Levene test), one-way ANOVA was applied to test for<br />
significance of differences among the tested groups, followed<br />
by Tukey’s test for post-hoc comparisons. In all the<br />
analyses, the level of significance was set at α = 95%.<br />
RESULTS<br />
The bond strength values found in this investigation are reported<br />
in Fig 1 and Tables 2 to 4.<br />
276 The Journal of Adhesive Dentistry
Raffaelli et al<br />
Table 2 Bond strength values obtained luting 3-mm-thick<br />
porcelain disks. n=sample size (in parentheses, number<br />
of premature failures), mean, and standard deviation (SD)<br />
values excluding premature failures. Premature failures<br />
were excluded from the statistical analysis<br />
Group N Mean (MPa) SD<br />
1. (control): 42 (7) 20.9 BC 10<br />
PBNT LC +<br />
Calibra DC<br />
2. XP LC + 53 (8) 24.9 AB 10.7<br />
Calibra DC<br />
4. XP + SCA + 37 (4) 29.8 A 12.9<br />
Calibra DC<br />
According to the post-hoc test, XP+SCA+Calibra DC achieved a significantly<br />
higher bond strength than group 1. Groups with the same uppercase<br />
letter are not statistically significantly different.<br />
Table 3 Bond strength values obtained luting 2-mm-thick<br />
porcelain disks. n=sample size (number of premature failures<br />
in parentheses), mean and standard deviation (SD)<br />
values excluding premature failures. Premature failures<br />
were excluded from the statistical analysis<br />
Group N Mean (MPa) SD<br />
3. XP+ SCA + 35 (4) 23.6 AB 11.1<br />
Calibra DC<br />
6. XP + SCA + 37 (6) 28.6 A 10.4<br />
Calibra CC<br />
7. Syntac No LC 20 (17) 17.1 B 6.6<br />
+ Calibra CC<br />
According to the post-hoc test, XP+SCA (No LC)+Calibra CC achieved a<br />
significantly higher bond strength than Syntac No LC+Calibra CC.<br />
Groups with the same uppercase letter are not statistically significantly<br />
different.<br />
Table 4 Bond strength values recorded using 3 different porcelain thicknesses.<br />
n=sample size (number of premature failures in parentheses), mean and standard<br />
deviation values excluding premature failures. Premature failures were excluded<br />
from the statistical analysis<br />
Ceramic Adhesive/ n Mean (MPa) SD<br />
thickness resin cement<br />
Group 3: XP+SCA+Calibra 35 (4) 23.6 B 11.1<br />
2 mm DC<br />
Group 4:<br />
3 mm 33 (4) 29.8 AB 12.1<br />
Group 5:<br />
4 mm 43 (10) 30.3 A 12.3<br />
According to the post-hoc test, the bond strengths measured with 4-mm-thick disks were significantly<br />
higher than those measured with 2-mm-thick disks. Groups with the same uppercase letter are not statistically<br />
significantly different.<br />
Groups 4, 5, and 6 showed the highest bond strength values.<br />
In these three groups, the XP BOND was not light cured<br />
before seating the ceramic onlay, and in group 6 Calibra was<br />
chemically cured. When comparing the groups that differed<br />
in ceramic onlay thickness, it was noted that the specimens<br />
obtained from 4-mm-thick onlays (group 5) showed the highest<br />
bond strength but also a higher percentage of pretest<br />
failure.<br />
SEM observations showed that adhesive fracture was<br />
the most common failure type in groups 2 to 7. Only in group<br />
1 were two cohesive failures in dentin and two mixed failures<br />
recorded.<br />
DISCUSSION<br />
The microtensile evaluation performed in this study was<br />
used in order to standardize the bond strength test and evaluate<br />
two different variables, the restorative material thickness<br />
and the curing mode of the adhesive-luting agent combinations.<br />
In order to properly apply the statistical analysis,<br />
it was decided to report the number of premature failures in<br />
the tables without including them in the analysis. Only in<br />
group 7 was the number of premature failures rather high<br />
(45%). In the other groups, the percentage of premature failures<br />
was 10% to 19%. The occurrence of premature failures<br />
may be due to the stress transmitted at the bonding interface<br />
during the specimen reparation procedure.<br />
Vol 9, Supplement 2, 2007 277
Raffaelli et al<br />
Fig 1 Bond strength values (without<br />
premature failures) and percentage of<br />
premature failures (ptf) of the seven<br />
tested groups. NC: not cured; LC: light<br />
cured; DC: dual cured; CC: chemically<br />
cured.<br />
The results of this study demonstrated that the thickness<br />
of the porcelain restoration does not affect the polymerization<br />
of the adhesive/luting combination: in the three groups<br />
(3 to 5) in which the thickness of porcelain disks was 2, 3,<br />
and 4 mm, respectively, the bond strength values were between<br />
23.6 and 30.3 MPa with a progressive increase of<br />
bond strength proportional to the porcelain thickness. This<br />
could be due to the efficacy of the self-curing mode of the<br />
new bonding material and/or to the intrinsically greater<br />
strength of thicker porcelain. This result should lay to rest<br />
any doubts that a thick ceramic restoration cannot be luted<br />
using a one-bottle system in combination with a resin cement.<br />
The results also suggest that XP BOND can be considered<br />
a proper bonding system for luting full and partial porcelain<br />
crowns. In order to simplify the clinical luting procedures and<br />
according to the results of this study, XP BOND and Calibra<br />
resin cement can routinely be used in the self-curing mode.<br />
A study on the clinical performance of XP BOND cured by the<br />
application of its self-activator and used in combination with<br />
Calibra resin cement is currently ongoing.<br />
CONCLUSIONS<br />
From the results of this study the following conclusions can<br />
be drawn:<br />
XP BOND can be used in the self-curing mode in combination<br />
with SCA and Calibra resin cement for luting porcelain<br />
restorations.<br />
The porcelain restoration thickness is not a limitation to<br />
the curing process of the adhesive-luting material combination<br />
when XP BOND is self-activated.<br />
ACKNOWLEDGMENTS<br />
This research was sponsored by <strong>Dentsply</strong> DeTrey, Konstanz, Germany.<br />
REFERENCES<br />
1. Bergman MA. The clinical performance of ceramic inlays: a review. Aust Dent<br />
J 1999;44:157-168.<br />
2. Davidson CL. Luting cement, the stronghold or the weak link in ceramic<br />
restorations. Adv Engineer Mater 2001;3:763-767.<br />
3. De Munck J, Vargas M, Van Landuyt K, Hikita K, Lambrechts P, Van Meerbeek<br />
B. Bonding of an auto-adhesive luting material to enamel and dentin. Dent<br />
Mater 2004;20:963-971.<br />
4. Hahn P, Schaller HG, Hafner P, Hellwig E. Effect of different luting procedures<br />
on the seating of ceramic inlays. J Oral Rehabil 2000;27:1-8.<br />
5. Pashley DH, Pashley EL, Carvalho RM, Tay FR. The effects of dentin permeability<br />
on restorative dentistry. Dent Clin North Am 2002;46:211-245.<br />
6. Shono Y, Terashita M, Shimada J, Kozono Y, Carvalho RM, Russell CM, Pashley<br />
DH. Durability of resin-dentin bonds. J Adhes Dent 1999;1:211-218.<br />
7. Tay FR, Frankenberger R, Krejci I, Bouillaguet S, Pashley DH, Carvalho RM,<br />
Lai CN. Single-bottle adhesives behave as permeable membranes after polymerization.<br />
I. In vivo evidence. J Dent 2004;32:611-621.<br />
8. Tay FR, Pashley DH, Suh BI, Hiraishi N, Yiu CK. Water treeing in simplified<br />
dentin adhesives - déjà vu Oper Dent 2005;30:561-579.<br />
9. Tay FR, Pashley DH. Dental adhesives of the future. J Adhes Dent 2002;4:91-<br />
103.<br />
10. Van Meerbeek B, De Munck J, Yoshida Y, Inoue S, Vargas M, Vijay P, Van Landuyt<br />
K, Lambrechts P, Vanherle G. Buonocore memorial lecture. Adhesion to<br />
enamel and dentin: current status and future challenges. Oper Dent<br />
2003;28:215-235.<br />
Clinical relevance: The results of this microtensile investigation<br />
show good performance of XP BOND in its self-curing<br />
mode.<br />
278 The Journal of Adhesive Dentistry
XP BOND in Self-curing mode used for Luting Porcelain<br />
Restorations. Part B: Placement and 6-month Report<br />
Marco Ferrari a /Ornella Raffaelli b /Maria Crysanti Cagidiaco c /Simone Grandini d<br />
Purpose: The aim of this clinical study was to evaluate the postoperative sensitivity of Empress II restorations luted under<br />
clinical conditions with XP BOND in combination with SCA and Calibra cured in self-curing mode.<br />
Materials and Methods: Fifty-three restorations were placed in 38 patients in March and April 2006. No patient received<br />
more than two restorations. Luting procedures were performed following manufacturers’ instructions. The restorations<br />
were evaluated after 2 weeks and 6 months for postoperative sensitivity, marginal discoloration, marginal integrity, secondary<br />
caries, maintenance of interproximal contact, and fracture.<br />
Results: At the 2-week recall, the postoperative sensitivity was reported in only 10 and after 6 months in only 3 patients.<br />
All other parameters showed alpha scores.<br />
Conclusion: All the evaluated restorations were in place and acceptable. The postoperative sensitivity recorded after<br />
using XP BOND and Calibra in self-curing mode was clinically acceptable.<br />
Keywords: ceramic crowns, self-curing, clinical trial, bonding.<br />
J Adhes Dent 2007; 9: 279-282. Submitted for publication: 15.12.06; accepted for publication: 11.1.07.<br />
Indirect ceramic restorations are a valid alternative to direct<br />
esthetic restorations and to porcelain-fused-to-metal<br />
crowns. The prerequisite for application of full and/or partial<br />
porcelain crowns is perfect bonding, which has to integrate<br />
all parts into one coherent structure. 6 Therefore, luting material<br />
and technique as well as the substrate characteristics<br />
represent the factors determining success. 7<br />
a Dean, Professor, and Chair, Department of Dental Materials and Prosthodontics,<br />
University of Siena, Siena, Italy.<br />
b PhD Student, Department of Dental Materials and Prosthodontics, University<br />
of Siena, Siena, Italy.<br />
c Assistent Professor, Department of Dental Materials and Prosthodontics, University<br />
of Siena, Siena, Italy.<br />
d Chair, Assistent Professor, Department of Endodontics, University of Siena,<br />
Siena, Italy.<br />
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,<br />
September 13th, 2006<br />
Reprint requests: Prof. Marco Ferrari, Research Center for Dental Health, 19<br />
Piazza Attias, 57120 Livorno, Italy. Tel: +39-586-892-283, Fax: +39-586-898-<br />
305. e-mail: ferrarimar@unisi.it<br />
Different combinations of adhesive luting materials have<br />
been tested, and dual-curing bonding systems are often the<br />
first choice. 3,5,8,12,14-16,18,19,21 Dual-curing bonding agents<br />
permit polymerization of the adhesive materials and the<br />
resin cement underneath a thick ceramic restoration. Recently,<br />
XP BOND (<strong>Dentsply</strong> DeTrey; Konstanz, Germany) was<br />
proposed and tested experimentally, showing interesting data<br />
when the adhesive was used in self-curing mode. 20<br />
Postoperative sensitivity is a common complication when<br />
porcelain crowns are luted on vital teeth. 9 The aim of the present<br />
prospective clinical trial was to evaluate the early postoperative<br />
sensitivity of Empress II restorations (Ivoclar-Vivadent;<br />
Schaan, Liechtenstein), cemented under clinical<br />
conditions with the adhesive system XP BOND/SCA and Calibra<br />
resin cement (<strong>Dentsply</strong> Caulk; Milford, DE, USA), both<br />
used in self-curing mode.<br />
MATERIALS AND METHODS<br />
The sample consisted of 53 consecutively placed restorations<br />
in 38 patients in need of one or two single units. Par-<br />
Vol 9, Supplement 2, 2007 279
Ferrari et al<br />
Table 1 Changes in pre- and postoperative sensitivities (1 = lowest, 10 = highest<br />
sensitivity)<br />
case<br />
XP Bond / SCA / Calibra [n]<br />
Type of Pre- Postoperative Postoperative<br />
restoration operative sensitivity sensitivity<br />
sensitivity (2 weeks (6 months<br />
after<br />
after<br />
placement)<br />
placement)<br />
1 Inlay (OD) 0 6 3<br />
2 Inlay (MOD) 0 1 0<br />
3 Inlay (MO) 0 1 0<br />
4 2 onlays 2 0 0<br />
5 Onlay 0 1 0<br />
6 Inlay (MOD) 3 1 0<br />
and onlay<br />
7 Inlay (MO) 0 1 0<br />
8 Onlay 4 1 0<br />
9 Onlay 0 3 2<br />
10 Inlay (MOD) 0 1 0<br />
11 Inlay (MOD) 0 3 2<br />
tial or full restoration was performed from the pool of patients<br />
accessing the department of Restorative Dentistry of<br />
the University of Siena. Patients’ written consent to the trial<br />
was obtained after having provided a complete explanation<br />
of the aim of the study.<br />
Inclusion and Exclusion Criteria<br />
Males and females aged 18 to 60 years in good general and<br />
periodontal health were included. Patients to whom the following<br />
factors applied were excluded from the clinical trial:<br />
1. Under 18 years of age<br />
2. Pregnancy<br />
3. Disabilities<br />
4. Prosthodontic restoration of tooth can be expected<br />
5. Pulpitic, nonvital, or endodontically treated teeth<br />
6. (Profound, chronic) periodontitis<br />
7. Deep defects (< 1 mm from pulp) or pulp capping<br />
8. Heavy occlusal contacts or history of bruxism<br />
9. Systemic disease or severe medical complications<br />
10. History of allergy to methacrylates<br />
11. Rampant caries<br />
12. Xerostomia<br />
13. Lack of compliance<br />
14. Language barriers<br />
Test Stimuli and Assessment<br />
Before applying the adhesive material, a pain measurement<br />
was performed utilizing a simple pain scale based on the response<br />
method. Response was determined to a 1-s application<br />
of air from a dental unit syringe (at 40 to 65 psi at approximately<br />
20°C), directed perpendicularly to the root surface<br />
at a distance of 2 cm, and by tactile stimuli with a sharp<br />
#5 explorer. The patient was asked to rate the perception of<br />
the sensitivity experienced during this thermal/tactile stimulation<br />
by placing a mark on a visual analog scale (VAS) beginning<br />
at 0 and ending at 10 (where 0 = no pain and 10 =<br />
excruciating pain). In order to translate these scores into<br />
easily understood pain levels, a score of 0 was defined as<br />
no pain, 1 to 4 as mild sensitivity (which was provoked by the<br />
air blast), and 5 to 10 as strong sensitivity (which was spontaneously<br />
reported by the patient during drinking and eating).<br />
Only patients scoring low on the VAS were included in<br />
the study, whereas high score cases were excluded based<br />
on the assumption that irreversible pulp inflammation could<br />
be sustaining the high sensitivity. The status of the gingival<br />
tissues adjacent to the test sites was observed at baseline<br />
and at each recall. Patients were recalled to our department<br />
for testing postoperative sensitivity after 2 weeks and 6<br />
months.<br />
Clinical Procedure<br />
For standardization purposes, the same operator performed<br />
all the clinical procedures. Following anesthesia, the rubberdam<br />
was placed, all carious structures were excavated, and<br />
any restorative material was removed. Preparation was performed<br />
using conventional diamond burs in a high-speed<br />
handpiece with no bevel on margins. The preparation design<br />
was dictated by the extent of decay and pre-existing restorations.<br />
The residual dentin thickness (RDT) was evaluated on<br />
a periapical radiograph, and teeth with RDT thinner than 0.5<br />
mm were excluded. After preparation, the impression of the<br />
prepared tooth was taken and sent to the laboratory. A temporary<br />
restoration was performed. One week later, the ceramic<br />
restorations were luted. Luting procedures were performed<br />
under rubbes-dam. The cavity preparation was<br />
cleaned with a rotating brush and pumice, and then water<br />
280 The Journal of Adhesive Dentistry
Ferrari et al<br />
Table 2 Performance criteria according to Ryge<br />
Criteria and number of XP Bond<br />
restorations evaluated after SCA alpha bravo charlie delta<br />
6 months Calibra[n]<br />
Marginal discoloration and 53 53 0 0 0<br />
integrity<br />
Secondary caries 53 53 0 0 0<br />
Vitality test 53 53 0 0 0<br />
Interproximal contacts 53 53 0 0 0<br />
Retention 53 53 0 0 0<br />
Fracture 53 53 0 0 0<br />
sprayed and air dried carefully. 36% phosphoric acid gel was<br />
then applied for 15 s on enamel margins, and then for other<br />
15 s on dentin. The gel was removed with air spray and<br />
the surface blown gently with an air syringe. One drop of XP<br />
Bond was dispensed and mixed with one drop of self-curing<br />
activator. Using a microbrush, all cavity walls were wet and<br />
the adhesive material was left undisturbed for 20 s. After<br />
that, the solvent was evaporated by thoroughly blowing with<br />
air from an air syringe for 5 s. No light curing step was performed.<br />
Calibra Esthetic Resin Cement base and catalyst in<br />
similar amounts were mixed and applied on the cavity surface.<br />
Then the restoration was placed in the cavity preparation,<br />
and resin cement excess was removed with a clean microbrush.<br />
The Calibra cement was used in self-curing mode.<br />
The restorations were placed in March and April 2006 and<br />
examined for postoperative sensitivity at baseline, after 2<br />
weeks and 6 months by the same operator. At each recall,<br />
data on postoperative sensitivity, stability, and longevity<br />
were collected with reference to the USPHS criteria. Therefore,<br />
the following parameters were assessed:<br />
• postoperative sensitivity with the restoration under function,<br />
cold and warm stimuli, and a gentle air stream (on a<br />
scale from 0 to 10).<br />
• marginal discoloration and integrity<br />
• secondary caries<br />
• fracture<br />
• vitality test<br />
• retention<br />
• interproximal contacts<br />
The null hypothesis was that the self-curing mode does<br />
not affect postoperative sensitivity.<br />
RESULTS<br />
The results of postoperative sensitivities are summarized in<br />
Table 1. All 53 teeth were evaluated at baseline, and after 2<br />
weeks and 6 months. At baseline, 3 patients showed pre-operative<br />
sensitivity on 5 teeth. Ten cases of postoperative sensitivity<br />
were observed at the 2-week recall, but only 3 after<br />
6 months. At the 2-week recall, the postoperative sensitivity<br />
increased from 0 to 6 in one case immediately after luting<br />
the restoration (after the anesthetic wore off) but<br />
dropped to score 3 after 6 months. In 7 cases showing an<br />
increase in postoperative sensitivity after 2 weeks, the hypersensitivity<br />
disappeared completely after 6 months. In<br />
two cases, a residual postoperative sensitivity of score 2 remained<br />
after 6 months. No adverse events/effects occurred.<br />
All other parameters showed alpha scores (Table 2).<br />
DISCUSSION<br />
Ceramic crowns can be considered a safe type of restoration,<br />
and are reported to last longer than any other esthetic indirect<br />
restoration, 15 although many factors influence success,<br />
such as the kind of ceramic, luting agent, and extension of<br />
the lesion. Notwithstanding the restoration material, debonding<br />
and thus microleakage at the gingival margins – particularly<br />
if located below the cementoenamel junction – cannot<br />
be completely prevented. 1,8 All these factors are related to<br />
three subjects: patient, dentist, and material. 11<br />
In order to control for any additional source of variation besides<br />
the patient-related variability, one and the same operator<br />
placed all the restorations in this clinical trial. Inclusion<br />
and exclusion criteria were followed in order to obtain the<br />
Ethics Committee’s approval. The occurrence of postopera-<br />
Vol 9, Supplement 2, 2007 281
Ferrari et al<br />
tive sensitivity was found in around 19% of the restorations,<br />
with an average score of 1.9. Only in one case of ten was the<br />
postoperative sensitivity relatively high (score 6), while in<br />
other cases, the sensitivity was not spontaneous. However,<br />
at the 6-month recall, the score dropped from 6 (strong) to<br />
3 (mild). This observation is in agreement with a study that<br />
reported hypersensitivity to be the most common postoperative<br />
complication. 17<br />
The accurate fitting of the crown is another aspect that is<br />
worth mentioning, even though this property was not explicitly<br />
assessed in this paper. A good fitting of the ceramic<br />
restoration can prevent postoperative sensitivity and pulp<br />
complications. In several studies, it had been reported 12,19<br />
that the marginal wear of a composite luting cement can undermine<br />
the mechanical support. To prevent excessive marginal<br />
wear, it is therefore mandatory to have the narrowest<br />
possible gap between the cavity preparation and ceramic<br />
restoration. Optimal fit (ranging from 50 to 100 μm) is preferred,<br />
8 particularly if the margins extend below the cementoenamel<br />
junction. 7,9<br />
A proper adhesive-cement material combination is essential<br />
for avoiding postoperative sensitivity. Other self-activated<br />
bonding systems are available on the market and have<br />
been clinically tested. 5,14 All of them are usually both self-activated<br />
and light cured in order to guarantee complete polymerization<br />
of the bonding layer at the surface (where the<br />
bonding agent can be reached by light) and in deeper areas<br />
where light cannot penetrate to the adhesive layer.<br />
The dual-curing resin cements are used in combination<br />
with the proprietary bonding systems. Accordingly, with the<br />
limits of this study, the mixture of XP BOND with SCA in combination<br />
with chemically curing Calibra showed clinically acceptable<br />
levels of postoperative sensitivity at the 2-week<br />
and 6-month recalls. These findings will be reevaluated during<br />
next recalls at 12 months, and 2 and 3 years.<br />
The utilization of a correct bonding technique is mandatory<br />
to achieve good clinical results in ceramic inlay luting. 9<br />
In direct resin restorations, the bonding agent is routinely<br />
light cured prior to the insertion of the composite. In ceramic<br />
luting procedures, pre-curing of the adhesive resin may<br />
make restoration seating more difficult. Also in this regard,<br />
the use of a self-curing bonding agent is advantageous. In<br />
the present study, a self-curing cement was chosen for luting<br />
the restorations. The self-curing cements are able to<br />
achieve an adequate degree of conversion even at sites<br />
where light curing may be hindered by the thickness of the<br />
ceramic. The setting time of the resin cement can also be directly<br />
correlated to room temperature, glass plate, and<br />
mouth temperature.<br />
CONCLUSIONS<br />
XP BOND used in self-curing mode showed in only one case<br />
of 53 luted restorations a spontaneous postoperative sensitivity<br />
of medium intensity after 2 weeks, which dropped to<br />
a mild grade after 6 months, while all other 9 cases showed<br />
a very low degree of sensitivity.<br />
ACKNOWLEDGMENTS<br />
This research was sponsored by <strong>Dentsply</strong> DeTrey, Konstanz, Germany.<br />
REFERENCES<br />
1. Alavi AA, Kianimanesh N. Microleakage of direct and indirect composite<br />
restorations with three dentin bonding agents. Oper Dent 2002;27:19-24.<br />
2. Bergman MA. The clinical performance of ceramic inlays: a review. Aust<br />
Dent J 1999;44:157-168.<br />
3. Dagostin A, Ferrari M. In vivo bonding mechanism of an experimental dual<br />
cure enamel-dentin bonding system. Am J Dent 2001;14:105-108.<br />
4. Davidson CL. Luting cement, the stronghold or the weak link in ceramic<br />
restorations. Adv Engineer Mater 2001;3:763-767.<br />
5. Fabianelli A, Goracci C, Bertelli E, Davidson CL, Ferrari M. A clinical trial of<br />
Empress II Porcelain inlays luted to vital teeth with a self-light-curing adesive<br />
system and a self-curing resin cement. J Adhes Dent 2006;8:427-431.<br />
6. Ferrari M, Mason PN. Adaptability and microleakage of indirect resin inlays:<br />
an in vivo investigation. Quintessence Int 1993;24:861-865.<br />
7. Ferrari M, Mason PN, Fabianelli A, Cagidiaco MC, Kugel G, Davidson CL. Influence<br />
of tissue characteristics at margins on leakage of class II indirect<br />
porcelain restorations. Am J Dent 1999;12:134-142.<br />
8. Ferrari M, Dagostin A, Fabianelli A. Marginal integrity of ceramic inlays<br />
luted with a self curing resin system. Dent Mater 2003;19:270-276.<br />
9. Frankenberger R, Krämer N, Petschelt A. Technique sensitivity of dentin<br />
bonding: effect of application mistakes on bond strength and marginal<br />
adaptation. Oper Dent 2000;25:324-330.<br />
10. Hahn P, Schaller HG, Hafner P, Hellwig E. Effect of different luting procedures<br />
on the seating of ceramic inlays. J Oral Rehabil 2000;27:1-8.<br />
11. Hickel R, Manhart J. Longevity of dental restorations in posterior teeth and<br />
reasons for failure. J Adhes Dent 2001;3:45-64.<br />
12. Krämer N, Frankenberger R, Pelka M, Petschelt A. IPS Empress inlays and<br />
onlays after four years- a clinical study. J Dent 1999;28:325-331.<br />
13. Krämer N, Lohbauer U, Frankenberger R. Adhesive luting of indirect<br />
restorations. Am J Dent 2000;13:60-76.<br />
14. Krämer N, Frankenberger R. Clinical performance of bonded leucite –reinforced<br />
glass ceramic inlays and onlays after eight years. Dent Mater<br />
2005;21:262-271.<br />
15. Lee IB, Um CM. Thermal analysis on the cure speed of dual cured resin cements<br />
under porcelain inlays. J Oral Rehabil 2001;28:186-197.<br />
16. Manhart J, Scheibenbogen-Fuchsbrunner A, Chen HY, Hickel R. A 2-year<br />
clinical study of composite and ceramic inlays. Clin Oral Invest 2000;<br />
4:192-198.<br />
17. Manhart J, Chen HY, Neuerer P, Scheibenbogen-Fuchsbrunner A, Hickel R.<br />
Three-year clinical evaluation of composite and ceramic inlays. Am J Dent<br />
2001;14:95-99.<br />
18. Millediing P, Örtengren U, Karlsson S. Ceramic inlay systems: some clinical<br />
aspect. J Oral Rehabil 1995;22:571-580.<br />
19. Molin MK, Karlsson SL. A randomized 5-year clinical evaluation of 3 ceramic<br />
inlay systems. Int J Prosthodont 2000;13:194-200.<br />
20. Raffaelli O, Cagidiaco MC, Goracci C, Ferrari M. XP BOND in self-curing<br />
mode used for luting porcelain restorations. Part A: microtensile test. J<br />
Adhes Dent 2007;9:275-278.<br />
Clinical relevance: The results of this 6-month study reveal<br />
good clinical performance of XP BOND in self-curing<br />
mode.<br />
282 The Journal of Adhesive Dentistry
Sarrett<br />
Vol 9, Supplement 1, 2007 283