Indirect and Direct Restorative Protocols - Caulk
Indirect and Direct Restorative Protocols - Caulk
Indirect and Direct Restorative Protocols - Caulk
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<strong>Indirect</strong> <strong>and</strong> <strong>Direct</strong> <strong>Restorative</strong> <strong>Protocols</strong><br />
PROSTHETICS<br />
CAULK<br />
PROFESSIONAL<br />
H<strong>and</strong>pieces<br />
Carbide Burs<br />
Impression Materials<br />
Ceramic Systems<br />
Resin Cements<br />
Bonding Systems<br />
Composite Materials<br />
Polishing Instruments<br />
A Supplement to a<br />
Montage Media Corporation Publication<br />
Supported by an unrestricted educational<br />
grant provided by DENTSPLY International.
<strong>Indirect</strong> <strong>and</strong> <strong>Direct</strong> <strong>Restorative</strong> <strong>Protocols</strong><br />
Incorporating Contemporary<br />
<strong>Restorative</strong> Techniques<br />
The key to successful direct<br />
<strong>and</strong> indirect dental<br />
treatment lies in precise<br />
data capture <strong>and</strong> procedural<br />
excellence. Concepts<br />
in tooth preparation, a<br />
fundamental component<br />
of both direct <strong>and</strong> indirect<br />
restorations, continue<br />
to evolve in conjunction<br />
with advances in clinical<br />
techniques <strong>and</strong> increasing<br />
patient dem<strong>and</strong> for conservative<br />
dentistry.<br />
Gregori M. Kurtzman, DDS<br />
Private practice,<br />
Silver Spring, Maryl<strong>and</strong>.<br />
While material selection <strong>and</strong> treatment modalities<br />
continue to dictate the preparation design <strong>and</strong> amount of<br />
reduction required, contemporary<br />
instrumentation<br />
<strong>and</strong> materials have<br />
“The DENTSPLY<br />
family of products progressed as well, allowing<br />
dental professionals to<br />
gives the clinician an<br />
combine innovative technologies<br />
with traditional<br />
array of instruments<br />
<strong>and</strong> materials that techniques using an integrated<br />
family of restor-<br />
work seamlessly<br />
ative products.<br />
for any restorative<br />
Recent innovations in<br />
procedure.”<br />
material science <strong>and</strong> clinical<br />
instrumentation better<br />
enable one to monitor the<br />
degree of pressure being applied to the tooth surface <strong>and</strong><br />
thereby preserve sound tissue structures whenever possible.<br />
Using contemporary bur systems to create an optimal<br />
preparation design with smooth undercuts <strong>and</strong> margins,<br />
such innovations enable optimal data capture <strong>and</strong> transfer<br />
to be predictably achieved.<br />
Principles & Practices: <strong>Indirect</strong> <strong>and</strong> <strong>Direct</strong> <strong>Restorative</strong><br />
<strong>Protocols</strong> addresses tooth preparation considerations <strong>and</strong><br />
techniques, as well as the clinical procedures associated<br />
with aesthetic crown-<strong>and</strong>-bridge dentistry <strong>and</strong> direct resin<br />
restorations. This publication represents a cohesive review<br />
of practical techniques <strong>and</strong> a dedicated family of restorative<br />
products that can be applied to everyday dentistry,<br />
allowing the clinician to deliver optimal restorative care as<br />
a matter of routine. ■<br />
TABLE OF CONTENTS<br />
03 | H<strong>and</strong>piece Selection for Optimal Results<br />
in <strong>Restorative</strong> Dentistry<br />
07 | Appropriate Bur Selection: Proper Tooth<br />
Reduction for <strong>Indirect</strong> Restorations<br />
09 | Predictable Tissue Retraction: Methods<br />
<strong>and</strong> Techniques<br />
11 | Accurate Impression Making: Material<br />
Selection <strong>and</strong> Clinical Considerations<br />
15 | Aesthetic Provisional Restorations:<br />
Considerations <strong>and</strong> Influences on<br />
Prosthetic Outcomes<br />
18 | Developments in CAD/CAM: Ceramic<br />
Materials <strong>and</strong> Techniques<br />
21 | Cementation Guidelines: Clinical<br />
Recommendations <strong>and</strong> Requisites<br />
23 | Aesthetic Finishing <strong>and</strong> Polishing:<br />
Techniques for Ceramic Restorations<br />
25 | Instrumentation <strong>and</strong> Bur Selection for<br />
Minimally Invasive Tooth Preparation<br />
27 | <strong>Direct</strong> Resin Procedures for Aesthetics<br />
in Anterior Restorations<br />
29 | <strong>Direct</strong> Resin Restorations:<br />
Considerations for Adhesive Bonding<br />
31 | Finishing <strong>and</strong> Polishing Composite Resin<br />
Restorations: Clinical Parameters<br />
© 2008 Montage Media Corporation. All rights reserved.<br />
1
› PRINCIPLES & PRACTICES<br />
H<strong>and</strong>piece Selection<br />
for Optimal Results in<br />
<strong>Restorative</strong> Dentistry<br />
› Abstract:<br />
The dental h<strong>and</strong>piece is a<br />
mainstay in clinical practice.<br />
Numerous h<strong>and</strong>pieces are<br />
available, <strong>and</strong> selecting<br />
among their various features<br />
can have a considerable<br />
influence on the restorative<br />
outcome. The Midwest ®<br />
Stylus ATC h<strong>and</strong>piece<br />
(DENTSPLY Professional,<br />
York, PA), developed through<br />
a close partnership between<br />
manufacturer <strong>and</strong> clinician,<br />
combines the features<br />
of air-driven <strong>and</strong> electric<br />
h<strong>and</strong>pieces into a single<br />
instrument that provides the<br />
superior access, light weight,<br />
<strong>and</strong> comfort of the former<br />
with the power <strong>and</strong> efficiency<br />
of the latter.<br />
One of the most ubiquitous<br />
instruments in<br />
all of dentistry is the<br />
h<strong>and</strong>piece. Selecting the<br />
appropriate h<strong>and</strong>piece<br />
for any dental procedure solves many of<br />
the clinician’s concerns prior to his or<br />
her initiation of tooth reduction. The use<br />
of a h<strong>and</strong>piece that will address the full<br />
range of clinical applications is, therefore,<br />
critical to restorative success (Figure 1).<br />
The primary considerations when one is<br />
choosing a h<strong>and</strong>piece include: its power<br />
<strong>and</strong> torque (Figure 2), the cutting efficiency<br />
of the device, the access <strong>and</strong><br />
visibility it requires, <strong>and</strong> the unit’s ergonomics<br />
(Figure 3). A h<strong>and</strong>piece with<br />
constant cutting speed <strong>and</strong> adaptive<br />
capabilities affords the benefits of a highpowered<br />
h<strong>and</strong>piece <strong>and</strong> a precision refining<br />
instrument. The Midwest® Stylus<br />
ATC (DENTSPLY Professional, York,<br />
PA) h<strong>and</strong>piece offers the unique ability<br />
to instantly adapt to increased loads by<br />
increasing the power of the h<strong>and</strong>piece.<br />
Selection of a device with a rigid bur<br />
suspension will offer superior precision<br />
control for the development of precise<br />
margins. Ergonomics also play a key role<br />
in the practitioner’s selection of an appropriate<br />
unit. As h<strong>and</strong>pieces are used<br />
in virtually every aspect of dentistry, a<br />
lightweight, balanced unit such as the<br />
Stylus ATC will ensure operator comfort,<br />
improved tactile feel, <strong>and</strong> enhanced<br />
patient care.<br />
Visibility of the treatment site is important<br />
throughout care. H<strong>and</strong>pieces<br />
equipped with air <strong>and</strong> water spray not<br />
only aid in the cooling of the device but<br />
also help maintain a clear operating<br />
field for the operator, due to their small<br />
head size (Figure 4).<br />
In comparison to electric options,<br />
air-driven h<strong>and</strong>pieces are lighter in<br />
weight <strong>and</strong> offer smaller head designs<br />
Dentistry <strong>and</strong> photography<br />
courtesy of David A. Little, DDS,<br />
San Antonio, TX.<br />
Figure 1. The use of a<br />
powerful, hybrid air- <strong>and</strong><br />
electric-driven h<strong>and</strong>piece<br />
provides increased power<br />
<strong>and</strong> torque, with enhanced<br />
effi ciency for any type of<br />
tooth reduction.<br />
Removal of preexisting<br />
restorations is enhanced<br />
with a high-powered<br />
h<strong>and</strong>piece operating at<br />
a constant speed.<br />
3
Table. Combining Technologies:<br />
Air- <strong>and</strong> Electric-Driven H<strong>and</strong>piece<br />
For the fi rst time ever, air-driven <strong>and</strong> electric<br />
h<strong>and</strong>pieces are fused into a single h<strong>and</strong>piece<br />
system that delivers the power <strong>and</strong> effi ciency of<br />
an electric unit without sacrifi cing the superior<br />
access, lighter weight, <strong>and</strong> comfort of an airdriven<br />
h<strong>and</strong>piece.<br />
With activation of the rheostat, the Stylus<br />
ATC system:<br />
■ Accelerates to an optimal cutting speed.<br />
■ Continually monitors bur load.<br />
■ Automatically adjusts torque to maintain<br />
peak power.<br />
■ Limits speed when the bur is not under<br />
load to minimize potential wear on the<br />
h<strong>and</strong>piece bearings.<br />
Figure 2. A h<strong>and</strong>piece with powerful torque <strong>and</strong> adaptive power facilitates<br />
an effi cient, smooth preparation.<br />
H<strong>and</strong>piece water spray assists<br />
in cooling the bur <strong>and</strong> area<br />
being cut, <strong>and</strong> fl ushes away<br />
debris, improving visibility as<br />
the tooth is prepared.<br />
Figure 3. H<strong>and</strong>piece size <strong>and</strong> weight, as<br />
well as the size of the user’s h<strong>and</strong> <strong>and</strong><br />
his or her preferred position, should be<br />
considered when purchasing a high-speed<br />
h<strong>and</strong>piece for improved tactile feel during<br />
tooth reduction.<br />
4
“When using the Stylus ATC, the<br />
automated torque control feature<br />
eliminates the need for excess pressure<br />
during tooth reduction.”<br />
David A. Little, DDS<br />
Private practice, San Antonio, TX.<br />
Design Innovations of the Stylus ATC<br />
#4 The control source adjusts<br />
the torque over 700 times a<br />
second for a seamless delivery<br />
of performance, consistently<br />
maintaining peak power even<br />
under heavy loads.<br />
#1 A rigid suspension system allows for<br />
enhanced control for precise margins. In addition,<br />
the Midwest ® Stylus ATC h<strong>and</strong>piece<br />
system offers exceptional visibility, access,<br />
<strong>and</strong> maneuverability with both mini <strong>and</strong><br />
midsized heads.<br />
#2 An atomized<br />
cooling spray offers<br />
reliable cooling, while<br />
a fl ushing spray<br />
minimizes debris<br />
to provide greater<br />
visibility.<br />
#3 The Midwest ®<br />
Stylus ATC<br />
features brilliant<br />
fi ber optic<br />
illumination.<br />
#5 Integrated coupler <strong>and</strong><br />
tubing continually monitors<br />
bur speed <strong>and</strong> works with the<br />
control source to maintain<br />
performance <strong>and</strong> effi ciency.<br />
5
Figure 4. The small head of the Stylus ATC (DENTSPLY Professional,<br />
York, PA) enables visualization of the preparation site.<br />
A<br />
Figure 5A. The cutting effi ciency of the bur can be optimized by the<br />
Stylus ATC h<strong>and</strong>piece. 5B. Note the smooth tooth preparation<br />
achieved with minimal structural removal.<br />
B<br />
Table. Practical Tips for Using the Midwest ® Stylus ATC<br />
Tip<br />
Rationale<br />
Avoid excess<br />
pressure on the<br />
bur during tooth<br />
preparation ; there<br />
is no need to feather<br />
Lubricate <strong>and</strong> sterilize the h<strong>and</strong>piece<br />
prior to use in the operatory<br />
<strong>and</strong> between patients.<br />
Review proper<br />
air <strong>and</strong> water<br />
spray output<br />
prior to use.<br />
Verify that the bur<br />
is fully seated into<br />
the h<strong>and</strong>piece<br />
chuck.<br />
The device’s adaptive torque<br />
control reduces the amount of<br />
pressure needed for enhanced<br />
patient control <strong>and</strong> clinician<br />
comfort.<br />
Proper sterilization prevents<br />
cross contamination <strong>and</strong> potential<br />
health hazards, <strong>and</strong> it prolongs<br />
the life of the h<strong>and</strong>piece.<br />
A fi ne mist of water should be<br />
expressed using the unit, not<br />
a steady stream; increase the<br />
coolant air as needed until the<br />
desired mist is achieved.<br />
Full seating ensures most<br />
safe <strong>and</strong> effective use of the<br />
h<strong>and</strong>piece.<br />
for superior access in the oral cavity. The<br />
selection of an appropriate type of h<strong>and</strong>piece<br />
is dependent on the individual clinician<br />
<strong>and</strong> his or her practice. A h<strong>and</strong>piece<br />
system with an air-powered adaptive control<br />
combines air <strong>and</strong> electric control in a<br />
single unit (eg, Midwest® Stylus ATC,<br />
DENTSPLY Professional, York, PA) to<br />
provide the power <strong>and</strong> efficiency of electric<br />
h<strong>and</strong>pieces, without sacrificing the<br />
superior access, lighter weight, <strong>and</strong> familiar<br />
comfort of conventional high-speed<br />
units (Table).<br />
Developed through a unique partnership<br />
between industry manufacturers <strong>and</strong><br />
professionals, this instrument is the culmination<br />
of dental h<strong>and</strong>piece technology<br />
<strong>and</strong> unifies the leading features of previous<br />
electric <strong>and</strong> air-driven devices. As optimizing<br />
chairtime remains a key consideration<br />
motivating dental professionals, instrumentation<br />
such as the Stylus ATC thus<br />
represents a valuable addition to the clinical<br />
armamentarium used for proper tooth<br />
preparation <strong>and</strong> finishing (Figure 5). ■<br />
6
››Principles & Practices<br />
Appropriate Bur Selection:<br />
Proper Tooth Reduction<br />
for <strong>Indirect</strong> Restorations<br />
››Abstract:<br />
The continued evolution of<br />
dental adhesives <strong>and</strong> resin<br />
cements has modified the<br />
way clinicians approach the<br />
tooth preparation required<br />
for indirect restorations.<br />
While the biomechanical,<br />
micromechanical, <strong>and</strong> chemical<br />
properties of these adhesives<br />
have increased the potential for<br />
conservative tooth preparation,<br />
the instrumentation used to<br />
create such preparations<br />
must still perform the<br />
desired tooth reduction. This<br />
presentation highlights the role<br />
of proper bur selection in fixed<br />
prosthodontic care.<br />
The biomechanical, micromechanical,<br />
<strong>and</strong> chemical properties<br />
of contemporary dental<br />
adhesives <strong>and</strong> resin cements<br />
enable practitioners to adapt a<br />
more conservative approach to tooth preparation.<br />
In each such instance, the type of<br />
restorative procedure being performed will<br />
dictate the clinician’s choice of appropriately<br />
sized <strong>and</strong> shaped instrumentation.<br />
■ ■Straight, flat-end burs—Multi-<br />
Prep carbides (DENTSPLY Professional,<br />
York, PA) facilitate effective<br />
removal of existing composite, metal,<br />
or porcelain restorations. Their<br />
cross-cut shape ensures removal of<br />
debris from the preparation site <strong>and</strong><br />
requires less force to achieve the desired<br />
cutting action. <br />
■■Tapered, dome-end carbides—This<br />
MultiPrep shape enables rapid, efficient<br />
removal of composite resin,<br />
porcelain, <strong>and</strong> natural tooth structure<br />
<strong>and</strong> produces the divergent<br />
preparation walls required for allceramic<br />
crowns <strong>and</strong> aesthetic intracoronal<br />
restorations.<br />
■ ■ Flame-shaped, safe-end burs—<br />
In order to reduce the potential<br />
of injury to gingival tissues, some<br />
Midwest® burs such as the Flame<br />
include a smooth, non-cutting end<br />
that is less likely to cause damage or<br />
irritation when used at the gingival<br />
margin.<br />
In consideration for the varying tooth<br />
sizes among pediatric <strong>and</strong> adult patients,<br />
as well as the occlusal clearances that differ<br />
among younger <strong>and</strong> geriatric patients,<br />
it is also important to select a bur with the<br />
right shank length <strong>and</strong> style. Midwest®<br />
MultiPrep Burs (DENTSPLY Professional,<br />
York, PA) are available in numerous<br />
sizes <strong>and</strong> shapes to ensure the right option<br />
is available for the anatomical requisites of<br />
a given patient (Figure 1).<br />
When treating previously restored<br />
dentition, care should be taken to select<br />
Figure 1. Prior to initiating tooth reduction, care should be taken to<br />
ensure that the bur is properly secured in the h<strong>and</strong>piece chuck.<br />
Figure 2. Midwest ® dome-shaped crosscut burs facilitate removal of<br />
amalgam or other existing restorative materials <strong>and</strong> allow for easier<br />
entry into the tooth than flat-end burs.<br />
7
››“The Midwest metal-cutting burs have made<br />
removal of old crowns a quicker, less stressful<br />
experience, <strong>and</strong> they efficiently cut through whatever<br />
metal is used to fabricate the restoration.”<br />
Gregori M. Kurtzman, DDS<br />
Private practice, Silver Spring, MD.<br />
Figure 3. Cross-section view of the divergent walls, created with the tapered,<br />
round-end bur (MultiPrep, DENTSPLY Professional, York, PA),<br />
for the cavity preparation.<br />
Figure 4. Straight, flat-end burs can be utilized to finalize the walls <strong>and</strong><br />
floor of the preparation. Tapered burs create divergent walls with<br />
rounded internal line angles.<br />
Table. Tracking Individual Bur Usage<br />
It is important to track use on a bur-by-bur basis to reduce<br />
premature disposal or overuse of burs. Overuse may<br />
result in:<br />
■■ Instrument separation;<br />
■■ Excessive heat generation;<br />
■■ Damage to the h<strong>and</strong>piece; <strong>and</strong><br />
■■ Potential patient injury.<br />
Sterilization is also critical using a Cresent® Germicide Tray (DENTSPLY<br />
Rinn, Elgin, IL) <strong>and</strong> Bur Caddy / Bur Block (DENTSPLY Professional,<br />
York, PA) to safely disinfect bur systems with glutaraldehyde- <strong>and</strong><br />
phenol-based disinfectants. These caddies allow burs to be:<br />
■■ Individually sterilized;<br />
■■ Cleansed using a h<strong>and</strong>s-free approach to prevent<br />
contamination;<br />
■■ Kept separate from other burs in the kit; <strong>and</strong><br />
■■ Easily restocked following autoclaving.<br />
a bur <strong>and</strong> torque speed that will remove<br />
the existing restoration without<br />
impinging on the underlying tooth<br />
structures (Figure 2). Copious irrigation<br />
is also paramount to keeping the<br />
bur cool, prolonging its use (Table),<br />
<strong>and</strong> improving its cutting efficiency. It<br />
also ensures that the clinician can view<br />
the structures being removed, thereby<br />
reducing the potential for excessive<br />
tooth reduction. Once the preexisting<br />
restoration <strong>and</strong> carious structures have<br />
been removed, it is imperative to create<br />
divergent angles to facilitate retention<br />
of the definitive indirect restoration or<br />
convergent preparation walls to retain<br />
the restoration (Figure 3). Application<br />
of a cross-cut bur should only be implemented<br />
if additional gross reduction<br />
is required for extensive preparation<br />
designs (Figure 4). Once the desired<br />
preparation design has been achieved,<br />
the burs should be cleaned <strong>and</strong> carefully<br />
returned to the bur kit. n<br />
8
››Principles & Practices<br />
Predictable<br />
Tissue Retraction:<br />
Methods <strong>and</strong> Techniques<br />
››Abstract:<br />
Accurate data transfer<br />
between the clinician <strong>and</strong><br />
ceramist is critical for any<br />
indirect restorative procedure.<br />
A precise retraction technique<br />
is necessary to allow for<br />
reliable information transfer<br />
during impression making.<br />
Since different surfaces<br />
(eg, gingival tissues, dentin,<br />
enamels, <strong>and</strong> metals) have<br />
such varied moisture content,<br />
friction resistance, <strong>and</strong> surface<br />
tensions, clinicians should also<br />
use a reliable methodology<br />
in which each surface can be<br />
predictably optimized prior to<br />
impressing for the best<br />
possible results.<br />
S<br />
uccessful placement of a fixed<br />
dental prosthesis requires the<br />
clinician to accurately communicate<br />
the details of the patient’s<br />
intraoral environment to<br />
the laboratory technician. To capture this<br />
information, the practitioner must first<br />
control systemic factors (eg, periodontal<br />
health, crevicular fluid, inflammation) at<br />
the restorative site, create a proper margin<br />
design, <strong>and</strong> then make an impression of<br />
the required preparation. Additionally, he<br />
or she must displace or remove the gingival<br />
tissues that prevent the subsequently<br />
applied impression material from gaining<br />
access to a subgingival finish line.<br />
Care should, therefore, be taken to utilize<br />
proper methods of exposing subgingival<br />
finish line <strong>and</strong> to select a retraction cord<br />
that is resistant to fraying or tearing <strong>and</strong> that<br />
will not adhere to the dental tissues or the<br />
impression material. Although some cords<br />
are available in a pre-impregnated format to<br />
assist in hemostasis, it is generally advisable<br />
to utilize a hemostatic agent in order to limit<br />
the presence of fluids during impression<br />
capture <strong>and</strong> to ensure a clear, detailed margin<br />
(Figure 1). Localized anesthesia may be<br />
indicated for patients who require it, <strong>and</strong><br />
can be applied to one or several periodontal<br />
pockets in a needle-free application.<br />
Retraction Cords <strong>and</strong> Pastes<br />
When employing retraction devices, the<br />
primary concern is maintenance of clear<br />
finish lines <strong>and</strong> margins in order to ensure<br />
their capture <strong>and</strong> transfer to a detailed impression.<br />
Whether using a cord or paste retraction<br />
material (Table), proper packing<br />
also allows the impression material to flow<br />
subgingivally, which enables the soft tissue<br />
topography <strong>and</strong> prepared hard tissues<br />
to be properly recorded (Figure 2). When<br />
using retraction cord techniques, the clinician<br />
should:<br />
■■<br />
Create a lateral space of >0.5 mm;<br />
■■ Take care when using a heavy/rigid<br />
tray material to avoid locking an<br />
impression in undercuts;<br />
■■ Delay the impression procedure if<br />
adequate hemostasis cannot be<br />
achieved; <strong>and</strong><br />
■■ Maintain proper moisture control<br />
subgingivally.<br />
Figure 1. The retraction cord should be placed carefully to avoid soft<br />
tissue trauma <strong>and</strong> ensure precise marginal detail in the impression.<br />
Figure 2. Correct positioning of the retraction cord should be verified<br />
prior to impression making.<br />
9
››“The B4 Surface Optimizer helps me<br />
work faster by adapting each surface<br />
<strong>and</strong> readying the tissues for precise<br />
impression capture.”<br />
David Parker, DDS<br />
Private practice, Smithtown, NY.<br />
Figure 3. The cord is removed immediately prior to taking the impression,<br />
with caution exercised to avoid tearing the cord or damaging the<br />
soft tissues, which will cause sulcular bleeding <strong>and</strong> obscure marginal<br />
detail in the resulting impression.<br />
Figure 4. Use of the B4 ® Pre-impression Surface Optimizer (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) coats the hard <strong>and</strong> soft tissue surfaces to allow<br />
the syringed wash material to pass more easily over <strong>and</strong> around the<br />
surfaces to be impressed.<br />
Table. Achieving Predictable Tissue Retraction: Treatment Rationale<br />
Method Rationale Considerations<br />
Cords<br />
n Enhanced degree of mechanical displacement<br />
n Available with or without a hemostatic agent<br />
n Available in a variety of types <strong>and</strong> thicknessesto<br />
accommodate a range of procedures<br />
n Care must be taken to avoid soft tissue trauma<br />
n Often requires the use of local anesthesia<br />
n The ability to absorb hemostatic agents must<br />
be taken into account during cord selection<br />
Pastes<br />
n Completely atraumatic to soft tissue<br />
n Local anesthesia is not required<br />
n Expeditious application may be advantageous<br />
in multi-abutment situations<br />
n Vigorous rinsing is required for removal<br />
n Does not work well in narrow or shallow sulci<br />
n Does not provide the same degree of displacement<br />
as the cord technique<br />
Insertion <strong>and</strong> removal of the retraction<br />
cord should be performed<br />
with great care to avoid inflicting<br />
trauma to the soft tissue <strong>and</strong> ensure<br />
optimal patient comfort (Figure 3).<br />
Use of a pre-impression surface optimizer<br />
(B4®, DENTSPLY <strong>Caulk</strong>,<br />
Milford, DE) will further ensure<br />
predictable marginal accuracy <strong>and</strong><br />
precise data capture by coating the<br />
hard <strong>and</strong> soft tissues <strong>and</strong> allowing<br />
the wash material to better flow over<br />
<strong>and</strong> around them for improved accuracy<br />
(Figure 4).<br />
The highly wettable Aquasil Ultra<br />
Smart Wetting® Impression Material<br />
(DENTSPLY <strong>Caulk</strong>, Milford, DE) is designed<br />
to aid the clinician in maintaining<br />
adequate moisture control during<br />
the process. When using this hydrophilic<br />
material, the preparation area should be<br />
moist, but pooled liquid should first be<br />
removed with an evacuator to avoid the<br />
creation of an excessively moist field.<br />
When conducted accordingly, an impression<br />
material can thus flow subgingivally<br />
<strong>and</strong> capture the details of the tooth<br />
<strong>and</strong> ensure proper integration with the<br />
periodontal tissues. In fixed prosthodontic<br />
care, where the smallest subtleties have<br />
a considerable impact on the outcome of<br />
treatment, proper tissue management<br />
<strong>and</strong> tissue retraction are critical. n<br />
10
››Principles & Practices<br />
Accurate Impression Making:<br />
Material Selection <strong>and</strong><br />
Clinical Considerations<br />
››Abstract:<br />
Correct impression capture<br />
is paramount to overall<br />
restorative success. Clinicians<br />
are constantly challenged to<br />
provide clear margins free<br />
from tears <strong>and</strong> voids in order<br />
to allow multiple pours <strong>and</strong><br />
accurate reproduction of the<br />
intraoral environment within<br />
the laboratory. Communication<br />
is enhanced by the use of<br />
predictable materials that<br />
optimize this data transfer<br />
while creating a simplified,<br />
systematic approach designed<br />
for success.<br />
The impression remains the<br />
technician’s most valuable<br />
tool when developing an indirect<br />
restoration. Properly<br />
fitting restorations can only<br />
be fabricated if the dental laboratory is provided<br />
with a precise replica of the existing<br />
intraoral condition. Impression making,<br />
therefore, can be considered the most critical<br />
technique required for data transfer. A<br />
predictable execution of this procedure is<br />
subsequently required to ensure that the<br />
first impression captured is as accurate <strong>and</strong><br />
clear as possible (Figure 1; Table).<br />
As a precursor to the impression procedure,<br />
use of B4® Pre-Impression Surface<br />
Optimizer (DENTSPLY <strong>Caulk</strong>, Milford,<br />
DE) can equalize the surface tension of<br />
multiple substrates (eg, tooth, gingiva,<br />
implant), thereby allowing the impression<br />
material to achieve the desired flowability<br />
<strong>and</strong> detail. Voids <strong>and</strong> bubbles will be minimized<br />
for a more practicable impression,<br />
improving model surface details. A durable<br />
material such as Aquasil Ultra Smart Wetting®<br />
Impression Material (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) should then be selected<br />
to avoid tears, distortions, pulls, or drags<br />
in the impression itself. Its ability to adapt<br />
to tooth structures <strong>and</strong> the below the sulcus<br />
enables the practitioner to capture the<br />
details of the intraoral environment. Use of<br />
Aquasil Ultra Smart Wetting® Impression<br />
Material, with its favorable viscosities <strong>and</strong><br />
working time, ensures that the clinician is<br />
able to maintain <strong>and</strong> capture well-defined<br />
margins during the impression procedure<br />
(Figures 2 <strong>and</strong> 3). It can also be delivered<br />
via 50 mL cartridge, the digit® targeted delivery<br />
system (DENTSPLY <strong>Caulk</strong>, Milford,<br />
DE), or DECA 380 mL dynamic mixing<br />
machine cartridge (DENTSPLY <strong>Caulk</strong>,<br />
Milford, DE) according to the preference<br />
of the clinician.<br />
Once the impression is made to the clinician’s<br />
satisfaction, it must demonstrate<br />
Figure 1. Aquasil Ultra Smart Wetting ® Impression Material (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) can be used for all indirect restorative procedures.<br />
Figure 2. The dual-cord technique provides gingival retraction <strong>and</strong><br />
hemostasis at the treatment site during impression making.<br />
11
››<br />
“By combining the use of the B4 Surface Optimizer <strong>and</strong><br />
the Aquasil Ultra Smart Wetting Impression Material,<br />
even ultra thin margins are maintained, allowing multiple<br />
pours for increased communication with the laboratory.”<br />
Robert G. Ritter, DMD<br />
Private practice, Palm Beach Gardens, FL.<br />
Table. Clinical Considerations for Impression Capture<br />
Clinical Requisite<br />
Adequate<br />
gingival health<br />
Biologic space<br />
requirement<br />
Rationale<br />
Gingival inflammation may complicate hemostasis <strong>and</strong> moisture control; gingival<br />
assessment <strong>and</strong> transfer can also be compromised. Impressions should not be taken<br />
if inflammation cannot be controlled.<br />
Approximately 2 mm of distance is required between the restoration’s finish line <strong>and</strong> the<br />
alveolar crest to maintain the crestal bone level in comparison to the gingival margin.<br />
Appropriate<br />
tissue retraction<br />
Regardless of the specific technique selected, it is advisable to create a lateral space of<br />
approximately 1 mm <strong>and</strong> an apical extension beyond the finish line of approximately 1 mm.<br />
Bilateral cheek<br />
retraction<br />
Patients may bite asymmetrically if the cheek is retracted on one side only as the<br />
impression is taken; this technique may help to ensure proper centric occlusion is captured.<br />
Proper patient<br />
education<br />
Once the tray is seated, patients should refrain from any movements that could shift the<br />
position of the tray, thereby distorting the impression maintained.<br />
Figure 3. The impression is made using Aquasil Ultra Smart Wetting ®<br />
Impression Material (DENTSPLY <strong>Caulk</strong>, Milford, DE). Note its precise<br />
marginal detail.<br />
Figure 4. A centric bite registration should be captured for precise<br />
laboratory communication.<br />
12
››“Data transfer is critical to the fabrication of any restoration;<br />
use of a reliable impression material like Aquasil Ultra Smart<br />
Wetting allows development of models with precise<br />
margins devoid of undercuts <strong>and</strong> voids.”<br />
Nelson Rego, CDT<br />
Laboratory Technician <strong>and</strong> Owner, Rego Smiles, Santa Fe Springs, CA.<br />
Figure 5. A repeatable impression-making technique <strong>and</strong> Aquasil Ultra<br />
(DENTSPLY <strong>Caulk</strong>, Milford, DE) facilitate the fabrication of accurate<br />
restorations in the dental laboratory.<br />
Figure 6. Postoperative appearance demonstrates harmonious integration<br />
that was only possible due to precise data transfer <strong>and</strong> thorough<br />
communication with the laboratory.<br />
››Achieving Predictable Impression Capture<br />
■■<br />
■■<br />
■■<br />
■■<br />
■■<br />
Ensure proper tissue retraction <strong>and</strong> hemostasis.<br />
Properly dry the prepared tooth structures prior<br />
to impression capture (but do not desiccate).<br />
Apply B4 ® Pre-Impression Surface Optimizer to the<br />
prepared tooth, then air-thin, taking care not<br />
to rinse or dry the applied material.<br />
Fully load Aquasil Ultra Smart Wetting ® Impression<br />
Material prior to syringing Aquasil Ultra wash<br />
material around the final preparations.<br />
Begin expressing Aquasil Ultra wash material<br />
at the tissue margin <strong>and</strong> then cover the entire<br />
tooth surface.<br />
■■<br />
■■<br />
■■<br />
■■<br />
When coverage of the marginal area is complete,<br />
proceed coronally <strong>and</strong> circumferentially, keeping<br />
the syringe tip in the material as it is expressed.<br />
Align the First Bite ® impression tray parallel to the<br />
occlusal plane for proper vertical seating.<br />
Seat the impression tray using firm, steady pressure<br />
until Aquasil Ultra Smart Wetting ® Impression<br />
Material overflows from the tray within approximately<br />
1 minute from the beginning of syringing.<br />
Verify proper marginal detail prior to<br />
forwarding to the laboratory.<br />
adequate dimensional stability to withst<strong>and</strong> the subsequent<br />
transfer to the laboratory prior to model fabrication. This<br />
required dimensional stability, a defining characteristic of<br />
Aquasil Ultra, will also influence the technician’s ability to<br />
produce multiple refractory models following delayed pouring.<br />
Additional occlusal data can be sent to the laboratory in the<br />
form of a rigid bite registration (eg, Regisil® Rigid, DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) (Figure 4). To ensure that the occlusal<br />
data being sent is clearly communicated, excess material that<br />
extends onto the soft tissue region or to the height of the tooth<br />
contour should be removed using a scalpel blade or sharp scissors<br />
when seating the registration onto the model.<br />
Impression materials <strong>and</strong> techniques can vary depending<br />
on the type of restoration or clinical environment. Thus, it is<br />
beneficial that materials such as Aquasil Ultra <strong>and</strong> repeatable<br />
impression-making techniques enable dental professionals to<br />
deliver a well-integrated restoration for either the anterior or<br />
posterior region (Figures 5 <strong>and</strong> 6). n<br />
13
› PRINCIPLES & PRACTICES<br />
Aesthetic Provisional Restorations:<br />
Considerations <strong>and</strong> Infl uences<br />
on Prosthetic Outcomes<br />
› Abstract:<br />
Provisionalization is one of<br />
the most critical steps in<br />
indirect restoration. During<br />
this stage, the final diagnostic<br />
requirements are identified;<br />
patient function, expectations,<br />
<strong>and</strong> aesthetics are evaluated;<br />
<strong>and</strong> the clinician can ensure<br />
development of an optimal<br />
restoration by evaluating the<br />
patient during temporization.<br />
Long-term provisionalization<br />
as facilitated by a wearresistant,<br />
durable material<br />
such as Radica ® (DENTSPLY<br />
Prosthetics, York, PA) allows<br />
the clinician to assess critical<br />
aspects of the patient’s<br />
condition prior to delivery of<br />
the definitive restorations.<br />
Provisional restorations are<br />
essential in maintaining<br />
the health, aesthetics,<br />
<strong>and</strong> function of the<br />
patient during restorative<br />
therapy. The provisional restoration<br />
offers both dental patients <strong>and</strong> professionals<br />
an opportunity to evaluate<br />
the proposed restorative contours,<br />
length, <strong>and</strong> function of the definitive<br />
restoration (Figures 1 <strong>and</strong> 2). Serving<br />
as the patient’s “test drive” of the<br />
final restoration, a Radica® provisional<br />
(DENTSPLY Prosthetics, York, PA)<br />
will allow proper soft tissue maintenance<br />
<strong>and</strong> sculpting of the papillae<br />
(Figures 3 <strong>and</strong> 4). This biocompatible,<br />
light-cured provisional crown <strong>and</strong><br />
bridge material allows the patient to<br />
enjoy a natural apperance <strong>and</strong> function<br />
during long-term temporization<br />
periods, where many provisional<br />
materials (eg, acrylics) lose their ability<br />
to withst<strong>and</strong> the forces of the intraoral<br />
environment. The favorable<br />
wear resistance of Radica® considerably<br />
reduces the risk of provisional<br />
perforation during temporization <strong>and</strong><br />
risk of saliva, bacteria, <strong>and</strong> thermal<br />
irritants from compromising the intended<br />
treatment outcome.<br />
Due to their shape, color stability,<br />
<strong>and</strong> aesthetics, Radica® provisional<br />
restorations also enable the practitioner<br />
to establish expectations for patient<br />
outcomes (Table) <strong>and</strong> aid in the diagnostic<br />
phase of treatment. The user’s<br />
ability to efficiently layer enamel <strong>and</strong><br />
dentin materials, in combination with<br />
unique characterizations, provides the<br />
patient with natural-appearing provisional<br />
restorations during this critical<br />
interim period.<br />
In order to ensure the patient maintains<br />
full function during the temporization<br />
phase of treatment, occlusal<br />
adjustments should be performed<br />
prior to cementing the provisional<br />
restoration. Next, the Radica® provisional<br />
should be refined with carbide<br />
Figure 1. Case 1. Preoperative view demonstrates malalignment <strong>and</strong><br />
disharmony in the anterior aesthetic region.<br />
Figure 2. The use of an aesthetic provisional system allowed the<br />
patient to view the anticipated results <strong>and</strong> harmony while enabling<br />
the clinician to evaluate function, shape, <strong>and</strong> alignment.<br />
15
› “High-quality provisional restorations<br />
such as Radica are<br />
critical to my ability to deliver<br />
a predictable aesthetic result<br />
for my patients.”<br />
Mike Malone, DDS<br />
Private practice, Lafayette, LA.<br />
Figure 3. Case 2. Note the excessive crowding, malalignment, <strong>and</strong><br />
gingival height discrepancies evident preoperatively.<br />
Figure 4. Radica ® temporaries allowed the clinician to evaluate the<br />
anticipated restorative positioning <strong>and</strong> gingival contours following initial<br />
crown lengthening.<br />
Table. Benefits of Radica ® Provisional Restorations<br />
Characteristic<br />
Strength<br />
Aesthetics<br />
Ease of Use<br />
Polishing<br />
Benefit<br />
With a wear resistance comparable to defi nitive<br />
composite materials <strong>and</strong> a strength of 165MPa,<br />
Radica ® is the most durable provisional system on<br />
record in today’s market.<br />
Radica ® offers a variety of shades <strong>and</strong> dimensional<br />
stability for enhanced aesthetics, establishing<br />
expectations for patient outcomes.<br />
Radica ® is simple to mix <strong>and</strong> repair, reducing<br />
chairtime. If needed, Radica ® provisionals<br />
may be relined with Integrity ® Temporary<br />
Crown <strong>and</strong> Bridge Material or Triad ® VLC<br />
Provisional Material.<br />
The material possesses a high polishability for a<br />
plaque- <strong>and</strong> stain-resistant surface.<br />
burs such as Midwest® Esthetic Finishing<br />
Burs (DENTSPLY Professional, York, PA),<br />
<strong>and</strong> polished as necessary with a PoGo®<br />
Diamond Micro-Polisher (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE). It is then imperative<br />
to select a temporary cement material<br />
(eg, Integrity® TempGrip, DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) that has the flow <strong>and</strong><br />
consistency for optimal seating, low film<br />
thickness, <strong>and</strong> high strengths for reliable<br />
retention, <strong>and</strong> cohesive setup to enable<br />
thorough cleanup.<br />
As with any cemented restoration,<br />
care should be taken to clean the gingival<br />
margins following seating to prevent<br />
potential irritation of the soft tissues <strong>and</strong><br />
even potential subgingival post-procedure<br />
infection. Gradual pressure should be used<br />
to seat the provisional restoration, <strong>and</strong><br />
may be accompanied by a gentle rocking<br />
motion for optimal security. Care should<br />
be taken to avoid moving the restoration<br />
during the removal of excess cement. Once<br />
properly seated, adjustments may be made<br />
to the provisional as needed. ■<br />
16
› PRINCIPLES & PRACTICES<br />
Developments in CAD/CAM:<br />
Ceramic Materials<br />
<strong>and</strong> Techniques<br />
› Abstract:<br />
Advances in CAD/CAM technology<br />
have resulted in zirconia-based<br />
ceramic materials that offer<br />
exceptional strength, fracture<br />
toughness, <strong>and</strong> biocompatibility.<br />
The CAD/CAM process provides<br />
immediate data capture <strong>and</strong> accurate<br />
fit in the prosthesis, <strong>and</strong> it enables<br />
the dental technician to focus<br />
on aesthetics during restoration<br />
fabrication. Use of predictable<br />
clinical <strong>and</strong> laboratory techniques<br />
with CERCON ® Zirconia restorations<br />
offers dental professionals <strong>and</strong> their<br />
patients a high-strength, predictable<br />
restorative solution.<br />
The evolution of dental<br />
technologies such as<br />
CAD/CAM <strong>and</strong> zirconia<br />
ceramics continues to<br />
exp<strong>and</strong> the restorative<br />
alternatives available to the contemporary<br />
dental patient. The biocompatibility,<br />
strength, <strong>and</strong> durability of<br />
zirconia restorations fabricated via<br />
CAD/CAM makes them attractive<br />
for anterior <strong>and</strong> posterior indications.<br />
Although different philosophies may<br />
exist regarding the details of metalfree<br />
restoration preparation (eg, where<br />
to trim the occlusal edge), goals<br />
such as minimal, uniform reduction<br />
(Figures 1 <strong>and</strong> 2) <strong>and</strong> replication of<br />
the facial contours of the natural<br />
dentition remain critical in achieving<br />
aesthetic, lasting restorations.<br />
While these treatment objectives may<br />
have remained relatively fixed, the technology<br />
surrounding these procedures<br />
has advanced significantly with the<br />
introduction of the CERCON® system<br />
(DENTSPLY Prosthetics, York, PA), offering<br />
clinicians <strong>and</strong> laboratory technicians<br />
several opportunities to provide excellent<br />
patient care <strong>and</strong> superior aesthetic results<br />
(Table). Its modular offerings of CER-<br />
CON CAD design (Eye <strong>and</strong> Art) <strong>and</strong> the<br />
CERCON CAM (Brain) milling component<br />
enables users to add specific service<br />
offerings as warranted by business growth.<br />
CERCON® provides considerable flexibility<br />
in material selection as well. This<br />
Figure 1. A chamfer margin enables effi cient scanning using CERCON ®<br />
(DENTSPLY Prosthetics, York, PA). Buccolingual reduction of 0.8 mm to<br />
1.5 mm <strong>and</strong> 1.5 mm of occlusal reduction using a #7345 bur (Multi-<br />
Prep, DENTSPLY Midwest, York, PA) is optimal to ensure strength<br />
<strong>and</strong> prevent fracture.<br />
Figure 2. Following fabrication of the CERCON ® Zirconia substructure,<br />
the aesthetic porcelain layer is applied. Ceramco ® PFZ<br />
porcelains are then applied to deliver natural-looking results.<br />
18
› “The use of CERCON Zirconia frameworks allows<br />
clinicians the necessary load-bearing capability<br />
(>1,300 MPa) required to support both single-unit<br />
<strong>and</strong> long-span restorations.”<br />
David A. Little, DDS<br />
Private practice, San Antonio, TX.<br />
CAD/CAM system has the ability to mill<br />
all-ceramic zirconia restoration copings,<br />
as well as to mill a new polyurethane<br />
material, CERCON Base Cast, <strong>and</strong> then<br />
burn it out to fabricate PFMs conventionally.<br />
Dental restorations from systems<br />
such as CERCON® not only produce<br />
exceedingly accurate scans <strong>and</strong> digital<br />
models—virtually matching the<br />
patient’s natural intraoral morphology—but<br />
they also allow clinicians <strong>and</strong><br />
technicians to provide faster service,<br />
Benefits of CERCON ®<br />
■ Accuracy—Fast, precise CAD<br />
scans to 10 µm with the CERCON®<br />
Eye laser scanner.<br />
■ Aesthetics—The natural translucency<br />
of CERCON® Zirconia provides<br />
an excellent aesthetic foundation,<br />
which is further enhanced with<br />
the fluorescence of Ceramco®<br />
PFZ porcelain.<br />
■ Performance —At over 1,300 MPa<br />
of flexural strength, CERCON®<br />
crowns <strong>and</strong> bridges have a higher<br />
fracture resistance than other allceramics<br />
<strong>and</strong> are suitable for anterior<br />
or posterior restorations up to 47 mm<br />
in length.<br />
■ Versatility—Offers dental laboratories<br />
versatility with Compartis, an<br />
outsourcing service, <strong>and</strong> CERCON®<br />
Cast, a resin block for milling PFM<br />
<strong>and</strong> other frameworks.<br />
■ Simplicity—CERCON® restorations<br />
are cementable or bondable<br />
<strong>and</strong> use the same conservative tooth<br />
preparation as PFMs.<br />
■ Confidence—Proven to withst<strong>and</strong><br />
the test of time with over<br />
10 years of clinical success <strong>and</strong> a<br />
seven-year warranty against zirconia<br />
framework breakage.<br />
Figure 3. Translucent characterizations<br />
are then applied.<br />
Figure 4. Using an aesthetic layering<br />
technique with Ceramco ® PFZ porcelains,<br />
lifelike results are achieved.<br />
Figure 5. Preoperative view of failing<br />
PFM crowns that require replacement.<br />
Figure 6. View of the aesthetic CERCON ®<br />
crowns postoperatively, demonstrating<br />
harmonious integration.<br />
19
› “A distinct chamfer or rounded shoulder, very similar<br />
to a PFM preparation, enables effi cient scanning of my<br />
preparation <strong>and</strong> ensures the proper fi t of my CERCON<br />
Zirconia restorations.”<br />
Lou Graham, DDS<br />
Private practice, Chicago, IL.<br />
› Protecting Your Investment<br />
All-ceramic restorations offer superior<br />
aesthetics <strong>and</strong> represent a signifi cant investment<br />
on the part of the patient. Bruxism<br />
following treatment can cause fracturing,<br />
resulting in a failed restoration<br />
<strong>and</strong> the need for additional treatment.<br />
iNterra INoffi ce Nightguard (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) can help protect the<br />
investment by:<br />
■ Providing a comfortable fi t to ensure<br />
patient compliance;<br />
■ Cushioning the teeth to prevent<br />
damage to the restoration;<br />
■ Providing wear resistance to ensure<br />
that the restorations will remain<br />
protected for many years; <strong>and</strong><br />
■ Enabling a single-visit, in-offi ce solution<br />
that protects the patient’s new smile.<br />
With more than 45 million patients affected<br />
by bruxism, prescribing an iNterra<br />
INoffi ce Nightguard (DENTSPLY <strong>Caulk</strong>,<br />
Milford, DE) nightguard represents a clear<br />
long-term benefi t to the longevity of the<br />
restorations <strong>and</strong> the health of the patient.<br />
Nightguard images appear courtesy of Dr. Mike Malone, Lafayette, LA.<br />
to the benefit of both dental patient <strong>and</strong> professional. The<br />
development of complementary material technologies<br />
(eg, zirconia) has furthered the benefit of CAD/CAM to<br />
the dental field by ensuring long-lasting, durable results<br />
in all-ceramic restorations.<br />
Accurate preparation <strong>and</strong> impression taking are still<br />
required of the clinician to ensure accurate scanning by<br />
the selected CAD/CAM system. Precise fit of the final<br />
restoration <strong>and</strong> the artistry of the laboratory technician<br />
are also necessary to develop natural aesthetics (Figures<br />
3 through 6). The benefit of CAD/CAM technology is<br />
that it allows these professionals to dedicate more time to<br />
their art <strong>and</strong> their practice, while providing strong, aesthetic<br />
results faster. ■<br />
20
› PRINCIPLES & PRACTICES<br />
Cementation Guidelines:<br />
Clinical Recommendations<br />
<strong>and</strong> Requisites<br />
› Abstract:<br />
Cementation of an indirect<br />
restoration involves numerous<br />
variables that include the<br />
luting material itself <strong>and</strong> the<br />
clinical technique used to seat<br />
the veneer, crown, bridge,<br />
or inlay/onlay. Composite<br />
resin cements are often used<br />
in conjunction with dental<br />
adhesives <strong>and</strong> chemically<br />
bond to numerous restorative<br />
materials, facilitating their<br />
adaptation to a properly<br />
conditioned tooth surface. This<br />
presentation discusses a series<br />
of considerations <strong>and</strong> clinical<br />
requisites that can aid the<br />
practitioner in this important<br />
phase of treatment.<br />
In fixed prosthodontics, the clinician’s<br />
ability to achieve an aesthetic,<br />
functional outcome depends<br />
on a variety of factors that<br />
include the cementation protocol.<br />
The luting cement used in such procedures<br />
has to possess high compressive<br />
<strong>and</strong> tensile strengths in addition to serving<br />
as an adherent between the natural<br />
tooth structures <strong>and</strong> the selected restorative<br />
material. Among numerous other<br />
favorable characteristics of an ideal cement<br />
are its biocompatibility, radiopacity,<br />
ease of delivery (eg, h<strong>and</strong>ling, working<br />
time), <strong>and</strong> low film thickness. For<br />
their part, resin cements are categorized<br />
as one of the following based on their activation<br />
mechanism:<br />
■ Light-cured: Recommended for indirect<br />
ceramic or composite restorations<br />
less than 1.5 mm in thickness;<br />
■ Dual-cured: Ideal in porcelain veneers,<br />
composite veneers, <strong>and</strong> other<br />
indications in which light penetration<br />
is limited to 1.5 mm to 2.5 mm<br />
through a dental restoration;<br />
■ Chemically cured: Indicated for restorations<br />
(eg, all-ceramic crowns, metal<br />
restorations, intracoronal restorations<br />
greater than 2.5 mm in thickness) that<br />
will not transmit light upon seating.<br />
Care should always be taken to ensure<br />
that the cement’s shade is compatible with<br />
the desired restoration upon seating of a<br />
ceramic restoration (Figure 1). An ideal<br />
resin cement will possess strong adhesive<br />
properties <strong>and</strong> marginal integrity, <strong>and</strong> will<br />
protect against marginal microleakage (see<br />
Sidebar). Furthermore, its flow will be defined<br />
by the height <strong>and</strong> taper of the preparation;<br />
the higher <strong>and</strong> more cylindrical the<br />
preparation, the less cement will escape,<br />
<strong>and</strong> a greater cement line will be present.<br />
Once the fit of the ceramic restoration<br />
has been confirmed <strong>and</strong> its intaglio surface<br />
has been treated, the prepared teeth should<br />
be conditioned (Figures 2 <strong>and</strong> 3). Today’s<br />
total-etch <strong>and</strong> self-etch adhesives simplify<br />
the seating appointment by combining<br />
steps (ie, etching, priming, bonding) previously<br />
involving multiple components. If the<br />
total-etch technique is selected, the clinician<br />
Figure 1. Shade selection of the resin cement may signifi cantly affect<br />
the fi nal shade of all-ceramic restorations (Courtesy: D. Greenhalgh, Mill<br />
Creek, WA).<br />
Figure 2. Once the tooth is conditioned, the interior of the ceramic restoration<br />
should be treated with a silane coupling agent to improve adhesion<br />
<strong>and</strong> ensure a durable bond.<br />
21
› “SmartCem2 is a valuable addition to my practice<br />
because of the effi ciency <strong>and</strong> time savings it affords me<br />
as well as my patient during the seating appointment.”<br />
Ronald A. Feinman, DMD<br />
Private practice, Atlanta, GA.<br />
Figure 3. A coat of the resin cement (ie, SmartCem2, DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) is applied to all surfaces that will contact the prepared<br />
tooth to eliminate any voids that may occur during the seating of<br />
the restoration (Courtesy: R.A. Feinman, Atlanta, GA).<br />
Figure 4. A tack cure of the cement can often allow the clinician to<br />
remove gross excess prior to fi nal curing of the luting cement without<br />
dislodging the restoration. Interproximal fl ossing can complete removal<br />
of excess cement prior to fi nal curing.<br />
› Recommendations<br />
for Cement Selection<br />
<strong>and</strong> Application<br />
■ The resin cement <strong>and</strong><br />
adhesive should have<br />
compatible activation<br />
mechanisms (eg, dualcured<br />
resin with<br />
dual-cured adhesive);<br />
■ Conventional resin<br />
cements are often indicated<br />
for less-retentive<br />
tooth preparations;<br />
■ Postoperative sensitivity<br />
can be minimized<br />
through agents such<br />
as Calm-It Desensitizer<br />
(DENTSPLY <strong>Caulk</strong>,<br />
Milford, DE); <strong>and</strong><br />
■ The radiopacity of the<br />
cement should enable<br />
subsequesnt evaluation<br />
for marginal decay.<br />
can opt for Prime & Bond® NT or XP<br />
BOND (DENTSPLY <strong>Caulk</strong>, Milford, DE)<br />
prior to light curing <strong>and</strong> application of<br />
the resin cement. Each of these materials<br />
provides versatility for use in light- <strong>and</strong><br />
dual-cured indications <strong>and</strong> favorable<br />
bond strengths that surpass those of similar<br />
etch-<strong>and</strong>-rinse adhesives. For a less<br />
technique-sensitive adhesive procedure,<br />
a self-etching system such as Xeno® IV<br />
(DENTSPLY <strong>Caulk</strong>, Milford, DE) may be<br />
employed to facilitate bonding.<br />
A resin-based, self-adhesive cement<br />
such as SmartCem2 (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) might also be<br />
selected for its high strength <strong>and</strong><br />
convenience. Bonding is generally unnecessary<br />
with self-adhesive cements.<br />
This cement can be dispensed either<br />
via automix syringe or automix digit<br />
targeted delivery system according to<br />
the clinician’s preference; SmartCem2<br />
eliminates the time <strong>and</strong> inconveniences<br />
often associated with mixing or capsule<br />
activation. Its excellent retentive <strong>and</strong> mechanical<br />
strengths to dentin <strong>and</strong> enamel<br />
ensure that the cement bonds effectively<br />
to porcelain, composite, <strong>and</strong> metal<br />
restorations, <strong>and</strong> that SmartCem2<br />
effectively seals margins.<br />
Once SmartCem2 is applied to the<br />
restoration <strong>and</strong> placed on the prepared<br />
tooth (Figure 3), the restoration may be<br />
gently manipulated into place for optimal<br />
seating. The “gel phase” of SmartCem2<br />
(DENTSPLY <strong>Caulk</strong>, Milford, DE) starts<br />
approximately one to two minutes thereafter<br />
<strong>and</strong> lasts about one additional<br />
minute—providing the clinician with a<br />
favorable working time chairside. A tack<br />
cure of less than 10 seconds can also be<br />
used to initiate the gel phase. A scalpel<br />
<strong>and</strong> floss can then be used to remove any<br />
excess cement material (Figure 4). When<br />
the final curing has been completed, the<br />
indirect restoration can be smoothed<br />
lightly with a carbide finishing bur<br />
(eg, Midwest® Esthetic Finishing Bur,<br />
DENTSPLY Professional, York, PA) <strong>and</strong><br />
then polished to the desired appearance,<br />
with the clinician taking care to ensure<br />
its final luster <strong>and</strong> finish. ■<br />
22
››Principles & Practices<br />
Aesthetic Finishing & Polishing:<br />
Techniques for<br />
Ceramic Restorations<br />
››Abstract:<br />
Contemporary ceramic materials<br />
enable dental professionals to<br />
instill natural aesthetics <strong>and</strong><br />
luster in the restorations of<br />
their patients. The long-term<br />
function <strong>and</strong> performance of<br />
these restorations depend on<br />
numerous factors that include<br />
marginal integrity <strong>and</strong> the<br />
creation of a proper finish <strong>and</strong><br />
polish. Development of an optimal<br />
surface reduces stain <strong>and</strong> plaque<br />
accumulation, minimizes wear,<br />
<strong>and</strong> enhances the appearance of<br />
the definitive restoration. This<br />
presentation exhibits a simplified<br />
protocol for finishing <strong>and</strong> polishing<br />
ceramic restorations.<br />
The increased patient dem<strong>and</strong><br />
for restorations that<br />
closely resemble natural<br />
dentition in aesthetics<br />
<strong>and</strong> function has contributed<br />
to the development of ceramic materials<br />
that provide the needed strength,<br />
durability, <strong>and</strong> beauty to meet those<br />
expectations. Although porcelain restorations<br />
such as CERCON® Zirconia<br />
<strong>and</strong> Finesse® (DENTSPLY Prosthetics,<br />
York, PA) possess intrinsic optical properties<br />
such as opalescence, fluorescence,<br />
<strong>and</strong> translucency that enable clinicians<br />
to achieve beautiful outcomes for their<br />
patients, minor marginal finishing is<br />
needed in virtually every indirect treatment<br />
to remove excess cement or during<br />
finalization of aesthetics or the occlusion<br />
(Figure 1). The use of a systematic finishing<br />
technique following cementation<br />
will improve a restoration’s long-term<br />
performance <strong>and</strong> maintenance of its<br />
marginal integrity.<br />
Once the restoration is seated, excess<br />
cement must be carefully removed, as<br />
any residual cement or marginal roughness<br />
will lead to plaque retention <strong>and</strong> the<br />
associated gingival inflammation. This<br />
will compromise not only the biological<br />
integration of the restoration with the gingival<br />
tissues but also the aesthetics, leading<br />
to chronic marginal inflammation<br />
<strong>and</strong> a potential for recurrent marginal<br />
decay. The restoration, therefore, must<br />
remain as biocompatible as possible (eg,<br />
particularly where in contact with soft<br />
tissues) to provide mechanical strength<br />
<strong>and</strong> aesthetics. Non-cutting, safe-end tips,<br />
which are featured in most tapered burs<br />
in the Midwest® Esthetic Finishing Bur<br />
system (DENTSPLY Professional, York,<br />
PA), enable the clinician to finish gingival<br />
margins while protecting the soft tissues<br />
throughout the procedure (Figure 2).<br />
Prior to selecting or using finishing<br />
instrumentation of any kind, the<br />
clinician should examine his or her<br />
Figure 1. Although ceramic restorations are delivered from the dental<br />
laboratory with a high luster <strong>and</strong> accuracy, minimal reduction may be<br />
necessary following cementation.<br />
Figure 2. Soft tissues can be effectively protected during marginal finishing<br />
with a Midwest ® Esthetic Finishing Bur (DENTSPLY Professional,<br />
York, PA), which features a non-cutting tip on the end of the bur.<br />
Inset: Cement can be removed marginally without lacerating the soft tissue.<br />
23
“In comparison to other finishing burs<br />
I have used, I’ve found that Midwest’s<br />
Esthetic Finishing Burs create a<br />
smoother surface for my restorations.”<br />
Gregori M. Kurtzman, DDS<br />
Private practice, Silver Spring, MD.<br />
Figure 3. Egg-shaped carbides of the Midwest ® Esthetic Finishing line<br />
(DENTSPLY Professional, York, PA) are well suited for smoothing inconsistencies<br />
on the lingual aspects of the restorations.<br />
Figure 4. Midwest ® bullet-shaped <strong>and</strong> multi-fluted burs <strong>and</strong> carbides<br />
may be used to finish the occlusal surface.<br />
Table. Inspection Criteria for Finishing Burs<br />
First Use<br />
n Check for inadvertent damage that may have<br />
occurred while readying burs for use<br />
n Cutting edges should be free from defects<br />
n Long, slender burs should be checked for distortion<br />
n Discard damaged or distorted burs<br />
n Sterilize burs prior to first use<br />
Re-Use*<br />
n Check for damage that may occur during sterilization<br />
n Cutting edges should be free from defects<br />
n Long, slender burs should not be bent or damaged<br />
n Discard damaged or corroded burs<br />
n Ensure all contamination has been removed<br />
* Following sterilization, the instruments may exhibit some evidence of discoloration. This is normal <strong>and</strong> should not affect their performance.<br />
instruments to ensure their suitability for use in the intraoral<br />
environment (Table). Finishing with a bur possessing a low<br />
blade count can be inefficient, as it will often chatter in<br />
contact with the restoration surface <strong>and</strong> will destroy the<br />
innate properties of the ceramic material. Use of burs with<br />
a high blade count, such as 30-fluted, finishing carbides<br />
(Midwest® Esthetic Finishing Burs, DENTSPLY Professional,<br />
York, PA), however, can enable predictable fine<br />
finishing around the new restoration. With a wide assortment<br />
of anatomically adapted shapes in six different blade<br />
lengths, the Esthetic Finishing Burs ensure the clinician<br />
has the proper instrument available for finishing the varying<br />
morphology of the anterior <strong>and</strong> posterior regions (Figures<br />
3 <strong>and</strong> 4). These burs perform well for finishing transitions<br />
between natural tooth structures <strong>and</strong> ceramic restorations<br />
(eg, inlays/onlays, crowns), <strong>and</strong> for removing excess cement<br />
<strong>and</strong> flash from the margin.<br />
Effective trimming <strong>and</strong> finishing with Midwest® finishing<br />
burs ensures that oral health is maintained throughout the entire<br />
lifespan of the restoration. A rough ceramic surface may<br />
promote the retention of plaque <strong>and</strong> bacteria, leading to periodontal<br />
disease <strong>and</strong> caries. Gingival irritation resulting from a<br />
rough surface may exacerbate these problems. These associations<br />
are not limited to anterior restorations; a poorly finished<br />
occlusal surface also puts the patient at risk for increased wear<br />
of the opposing dentition due to the different texture, stain retention,<br />
<strong>and</strong> microcracking of the rough ceramic surface. An<br />
effectively finished <strong>and</strong> polished ceramic surface is, therefore,<br />
necessary to ensure optimal oral aesthetics <strong>and</strong> to increase longevity<br />
of the restored tooth <strong>and</strong> dentition. n<br />
24
› PRINCIPLES & PRACTICES<br />
Instrumentation <strong>and</strong> Bur Selection<br />
for Minimally Invasive<br />
Tooth Preparation<br />
› Abstract:<br />
Significant improvements in the oral<br />
health of the worldwide population <strong>and</strong><br />
increasing patient interest in aesthetic<br />
dentistry have resulted in an emphasis<br />
on minimally invasive treatment<br />
options. Conservative treatment of<br />
diseased tooth structures is a valuable<br />
part of a modern <strong>and</strong> comprehensive<br />
approach to the management of<br />
the dentition. This presentation<br />
will discuss preparation design <strong>and</strong><br />
instrumentation required to deliver<br />
minimally invasive dental treatment,<br />
highlighting key considerations <strong>and</strong><br />
illustrating design requirements.<br />
Minimally invasive<br />
dentistry is in part<br />
a byproduct of<br />
clinicians’ greater<br />
underst<strong>and</strong>ing of<br />
the cavitation process <strong>and</strong> the therapeutic<br />
benefits of adhesive dentistry.<br />
The ultimate objective of minimally<br />
invasive dentistry is the preservation<br />
of tooth structure for strength <strong>and</strong><br />
long-term function. Innovative diagnostic<br />
devices such as Midwest Caries<br />
I.D. (DENTSPLY Professional,<br />
York, PA) <strong>and</strong> other means of caries<br />
detection have supported the transition<br />
to minimally invasive dentistry,<br />
thus better enabling the practitioner<br />
to conservatively respond to the oral<br />
health needs of today’s patient. Management<br />
of patients with dental caries<br />
involves careful treatment planning<br />
as well as the selection of appropriate<br />
instrumentation during restorative<br />
care (Figure 1). Proper maintenance<br />
<strong>and</strong> home care are also important in<br />
managing the caries-prone patient.<br />
If an area is suspected to have caries<br />
involvement, detection—either<br />
through conventional methods (eg,<br />
radiographs, explorers) or technological<br />
means such as with Midwest<br />
Caries I.D.—is important as the<br />
clinician attempts to prevent the<br />
caries process from progressing. Any<br />
such exploration should be as conservative<br />
as possible <strong>and</strong> confined to<br />
tooth enamel.<br />
When preparing for exploration<br />
or direct restoration of initial caries,<br />
access should be performed using<br />
Figure 1. Tapered, round-end burs (ie, Midwest ® Esthetic Finishing<br />
Bur, DENTSPLY Professional, York, PA) are well suited for conservative<br />
preparation along the buccal grooves of the tooth.<br />
Figure 2. Use of a 1/4 small round carbide (Esthetic Finishing Burs,<br />
DENTSPLY Professional, York, PA) allows conservative access to caries.<br />
Preservation of tooth structure is the key to conservative dentistry.<br />
25
› “Midwest carbides have helped me conservatively<br />
prepare teeth for direct restorations <strong>and</strong> rapidly remove<br />
compromised tooth structure in the process.”<br />
Gregori M. Kurtzman, DDS<br />
Private practice, Silver Spring, MD.<br />
Figure 3. Divergent walls of the preparation can be created using a<br />
tapered round-end bur, which improves overall retention of the direct<br />
resin restoration.<br />
Figure 4. Note the resulting groove along the occlusal anatomy of the<br />
tooth as it is prepared for minimally invasive therapy consisting of fl owable<br />
resin placement.<br />
a ¼ small round bur (Midwest® Operative Bur, DENTSPLY<br />
Professional, York, PA) for minimal intervention that is<br />
limited to the carious area (Figure 2). Throughout this procedure,<br />
the goal is to preserve sound tooth structure as a<br />
means of retaining the residual strength of the tooth <strong>and</strong> to<br />
serve as a substrate for the adhesion of composite resin.<br />
Once initial access has been achieved with the ¼ round<br />
bur, the clinician can use it or the ½ round shape to conservatively<br />
remove the existing caries. A direct “preventive”<br />
restoration with a flowable resin such as TPH®3 flow <strong>Restorative</strong><br />
(DENTSPLY <strong>Caulk</strong>, Milford, DE) can then be accomplished.<br />
This aesthetic, flowable composite can be efficiently<br />
delivered to posterior regions through a Compula® tip, <strong>and</strong><br />
the resin has radiopacity that enables effective monitoring<br />
by the clinician during subsequent maintenance visits.<br />
In the event that the caries progression extends beyond<br />
the dentoenamel junction, a Class I or II cavity preparation<br />
should be performed. The Midwest® tapered, round-end<br />
carbide (DENTSPLY Professional, York, PA) may be useful<br />
in such a preparation design (Figures 3 <strong>and</strong> 4); the clinician<br />
should keep the width of the preparation as narrow as<br />
possible <strong>and</strong> ensure all internal line angles are rounded <strong>and</strong><br />
cavity walls are smoothed in order to enable optimal resin<br />
adaptation upon placement. Carious dentin not removed<br />
during the initial access, <strong>and</strong> preparation can be accomplished<br />
using the ¼ small round bur (Midwest® Operative<br />
Bur, DENTSPLY Professional, York, PA). Once the dentin<br />
demonstrates a firm tactile response when an explorer is<br />
applied, removal of the tooth structure should cease. A horizontal<br />
layering of composite resin (eg, TPH®3 Micro Matrix<br />
<strong>Restorative</strong>, DENTSPLY <strong>Caulk</strong>, Milford, DE) can then be<br />
conducted to reduce volumetric polymerization shrinkage<br />
<strong>and</strong> cuspal flexure. The restoration can then be finished<br />
using 12-, 18-, <strong>and</strong> 30-fluted carbides (eg, Esthetic Finishing<br />
Burs, DENTSPLY Professional, York, PA) that accomplish<br />
successive trimming, smoothing, <strong>and</strong> cleaning of the direct<br />
buildup. Finishing <strong>and</strong> polishing with Enhance® <strong>and</strong> PoGo®<br />
systems (DENTSPLY <strong>Caulk</strong>, Milford, DE) can then be utilized<br />
to render the final appearance of the restored tooth<br />
with a smooth, natural-looking luster for optimal aesthetics<br />
<strong>and</strong> function.<br />
Minimally invasive dental procedures are gaining increased<br />
popularity for the treatment <strong>and</strong> the restoration<br />
of initial carious lesion defects. The ability of the adhesive<br />
restoration to reinforce residual sound tooth structure<br />
should be coupled with the selection <strong>and</strong> appropriate use<br />
of instrumentation in order to deliver the best outcome to<br />
the patient. ■<br />
26
› PRINCIPLES & PRACTICES<br />
<strong>Direct</strong> Resin Procedures<br />
for Aesthetics in<br />
Anterior Restorations<br />
› Abstract:<br />
The aesthetic expectations of<br />
today’s dental patients require<br />
the practitioner to have an<br />
innate underst<strong>and</strong>ing <strong>and</strong><br />
the clinical skills necessary<br />
to perform smile repair or<br />
enhancement. Composite<br />
resins such as Esthet•X ®<br />
Micro Matrix <strong>Restorative</strong><br />
(DENTSPLY <strong>Caulk</strong>, Milford,<br />
DE) possess physical <strong>and</strong><br />
aesthetic properties that<br />
facilitate the clinician’s ability<br />
to provide direct treatment<br />
with success <strong>and</strong> predictability.<br />
This presentation reviews<br />
guidelines that influence<br />
composite material selection<br />
as well as placement protocols<br />
used in their direct application.<br />
The increasing aesthetic expectations<br />
of dental patients<br />
dictate the use of state-of-theart,<br />
imperceptible anterior<br />
restorations for smile repair<br />
or enhancement. When treating a fractured<br />
tooth or repairing an existing restoration<br />
(Figure 1), it is necessary to mimic the aesthetics<br />
of the surrounding dentition <strong>and</strong><br />
to build up the resin restoration in a manner<br />
that matches the contours, length, <strong>and</strong><br />
width of the adjacent teeth. In selecting an<br />
appropriate shade, it is important to do so<br />
prior to the placement of a rubber dam to<br />
prevent improper shade matching due to<br />
dehydration or the tooth reflecting the color<br />
of the dam. For a Class IV fracture or repair<br />
of a porcelain veneer, a chamfer preparation<br />
is placed around the entire margin to increase<br />
the adhesive surface area, <strong>and</strong> a scalloped<br />
bevel should be used to break up the<br />
chamfer line. Once the preparation is complete,<br />
the tooth may be etched <strong>and</strong> a dental<br />
adhesive may be applied.<br />
The dentin layer may then be built up<br />
with a composite resin material using slow,<br />
steady pressure. For anterior procedures, a<br />
material that provides high strength <strong>and</strong><br />
polishability (eg, Esthet•X® Micro Matrix<br />
<strong>Restorative</strong>, DENTSPLY <strong>Caulk</strong>, Milford,<br />
DE) should be selected. The range of shades<br />
available in Esthet•X® ensures a successful<br />
treatment outcome, whether performed in<br />
a single-shade approach or an advanced<br />
technique involving multiple shades <strong>and</strong><br />
opacities. It has also demonstrated high<br />
fracture toughness in areas (eg, margins,<br />
incisal regions) that must withst<strong>and</strong> considerable<br />
intraoral forces.<br />
First, a thin layer of opaque dentin is applied<br />
(Figure 2). The regular body layer is<br />
then built up over the opacious layer (Figures<br />
3 <strong>and</strong> 4), followed by a translucent<br />
enamel layer to mimic the natural dentition<br />
(Figure 5). Care is taken to leave space<br />
for the successive increments of composite<br />
resin that will render the final appearance<br />
of the restoration. The contour <strong>and</strong> shape<br />
are adapted using the appropriate instruments,<br />
<strong>and</strong> then light cured. For the aesthetic<br />
blending of shades, additional body<br />
<strong>and</strong> enamel layers may be individually<br />
Figure 1. A Class IV anterior fracture, porcelain repair, or diastema<br />
closure present similar aesthetic challenges.<br />
Figure 2. Following preparation <strong>and</strong> surface conditioning, a thin layer of<br />
Esthet•X ® is placed against the lingual matrix to form the palatal shelf.<br />
27
“The aesthetic capabilities of the<br />
Esthet•X composite—such as its<br />
color matching <strong>and</strong> polishability—will<br />
allow the patient to show his or her<br />
smile with confi dence.”<br />
Mitch Conditt, DDS<br />
Private practice, Fort Worth, TX.<br />
Figure 3. A1-shaded composite resin (Esthet•X ® , DENTSPLY <strong>Caulk</strong>,<br />
Milford, DE) is used to replicate the mamelons of the natural tooth.<br />
Figure 4. Full contour is created using an additional increment of A1-<br />
shaded composite resin.<br />
Figure 5. A CE-shaded layer of Esthet•X ® is applied <strong>and</strong> contoured to<br />
match the adjacent central incisor.<br />
Figure 6. Predictable aesthetic results may be achieved in this operative<br />
dental procedure through the layering of composite resin materials with<br />
physical <strong>and</strong> optical qualities similar to those of the natural dentition.<br />
added to create a natural, aesthetic restoration. The final luster<br />
<strong>and</strong> appearance may then be achieved with appropriate<br />
finishing <strong>and</strong> polishing techniques (Figure 6). Differentiating<br />
the performance of Esthet•X® following such treatment<br />
is the material’s innate polish, which improves over<br />
time as the resin functions intraorally. This ensures lasting<br />
smoothness <strong>and</strong> a natural luster for the completed resin<br />
restoration. Esthet•X® also possesses radiopacity that enables<br />
simple review of its performance during subsequent<br />
evaluation by clinician <strong>and</strong> auxiliary staff. DENTSPLY<br />
<strong>Caulk</strong> has recently launched Esthet•X® HD (High Definition<br />
Micro Matrix <strong>Restorative</strong>), an upgrade to Esthet•X®.<br />
Esthet•X® HD offers excellent shading, h<strong>and</strong>ling, <strong>and</strong><br />
physical properties. With a newly optimized glass filler<br />
package, it now provides a faster, easier-to-achieve polish.<br />
Aesthetic repair or enhancement of anterior teeth is both<br />
feasible <strong>and</strong> predictable using contemporary composite<br />
resins. To achieve an optimal outcome, the aesthetic dentist<br />
needs only keen observational skills, patience, <strong>and</strong><br />
meticulous application of clinical technique. ■<br />
28
› PRINCIPLES & PRACTICES<br />
<strong>Direct</strong> Resin Restorations:<br />
Considerations for<br />
Adhesive Bonding<br />
› Abstract:<br />
It is the obligation of the<br />
practitioner to provide the<br />
dental patient with the most<br />
aesthetic restoration using<br />
clinical techniques that<br />
ensure proper function,<br />
biocompatibility, <strong>and</strong><br />
preservation of sound tooth<br />
structures. Composite resin<br />
materials <strong>and</strong> adhesive bonding<br />
techniques are well suited for<br />
such concepts of conservative<br />
dentistry. Consequently, a<br />
thorough underst<strong>and</strong>ing of<br />
adhesive bonding procedures<br />
<strong>and</strong> knowledge of adhesive<br />
material options are<br />
prerequisites in contemporary<br />
dental practice.<br />
During tooth preparation for<br />
a direct resin restoration,<br />
residual organic <strong>and</strong> inorganic<br />
components form a<br />
“smear layer” of debris on<br />
the tooth surface. This barrier decreases the<br />
permeability of dentin <strong>and</strong> must be removed<br />
or made permeable so that resin monomers<br />
or adhesives can contact <strong>and</strong> interact with<br />
the dentin surface. Two fundamental strategies<br />
are used to overcome the smear layer:<br />
■ Total-etch: Adhesive systems with an<br />
acid gel to condition dentin <strong>and</strong> enamel<br />
surfaces, dissolving the smear layer<br />
<strong>and</strong> 1 µm to 6 µm of hydroxyapatite.<br />
■ Self-etch: Adhesives that treat the<br />
dentin <strong>and</strong> enamel surfaces with a<br />
non-rinsed solution of acidic monomers<br />
in water. These bonding systems<br />
make the smear layer permeable to<br />
subsequently applied monomers.<br />
Etch-<strong>and</strong>-rinse adhesives used in the totaletch<br />
technique involve separate etching <strong>and</strong><br />
rinsing steps, followed by the application of<br />
a hydrophilic primer <strong>and</strong>/or bonding resin<br />
to produce a “hybrid layer” or resin-dentin<br />
interdiffusion zone. With an etch-<strong>and</strong>-rinse<br />
adhesive, the prepared tooth surface must<br />
remain slightly moist after the etching gel is<br />
rinsed away. Overdried dentin must be rewet<br />
in order to raise the collapsed collagen to<br />
a level suitable for bonding.<br />
One-bottle, etch-<strong>and</strong>-rinse adhesives<br />
such as Prime & Bond® NT (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) combine the primer<br />
<strong>and</strong> adhesive resin into a single step that<br />
achieves micromechanical interlocking of<br />
monomers with the collagen-rich etched<br />
dentin. The nanofiller technology of this<br />
material reinforces the hybrid <strong>and</strong> adhesion<br />
layer, protecting against microleakage <strong>and</strong><br />
postoperative sensitivity while establishing<br />
a proper marginal seal. Its combination of<br />
nanofillers <strong>and</strong> PENTA chemistry results<br />
in a material that eliminates postoperative<br />
sensitivity <strong>and</strong> ensures patient comfort.<br />
The chemistry of XP BOND Adhesive<br />
(DENTSPLY <strong>Caulk</strong>, Milford, DE), a universal<br />
self-priming adhesive, provides an<br />
extended working time <strong>and</strong> has a wider wetto-dry<br />
preparation tolerance than previous<br />
etch-<strong>and</strong>-rinse adhesives. Its ability to penetrate<br />
into the conditioned collagen network<br />
ensures the formation of an optimal bond.<br />
Figure 1. Preoperative view of defective fi lling that requires replacement<br />
with a direct composite resin restoration.<br />
Figure 2. Conservative cavity preparation is facilitated by adhesive-based<br />
approach that preserves sound tooth structures.<br />
29
“I use Xeno IV for my patients<br />
because of its simplicity <strong>and</strong> its<br />
ability to eliminate postoperative<br />
sensitivity in my patients.”<br />
Ronald A. Feinman, DDS<br />
Private practice, Atlanta, GA<br />
Figure 3. After conditioning of the enamel <strong>and</strong> dentin, an adhesive agent<br />
is applied with a fl ocked applicator to moisten the tooth surfaces.<br />
Figure 4. Finishing of the direct resin restoration is conducted using<br />
Enhance ® Finishers, followed by PoGo ® One-Step Diamond MicroPolishers<br />
for the fi nal polish.<br />
Table. Recommended Adhesive According to Clinician Profile<br />
User Consideration<br />
Prime &<br />
Bond ® NT XP Bond Xeno ® IV<br />
My preparation is confined to enamel ■ ■<br />
My preparation extends into the dentin layer<br />
■<br />
I occasionally have difficulty judging moisture levels on my conditioned cavity ■ ■<br />
Long-term clinical performance is more important to me than ease-of-use<br />
■<br />
Reducing my patients’ postoperative sensitivity is paramount<br />
■<br />
Marginal fit is imperative ■ ■ ■<br />
I generally prefer the total-etch technique ■ ■<br />
I usually employ the self-etch technique<br />
■<br />
I prefer the ease of application <strong>and</strong> simplified h<strong>and</strong>ling of a one-bottle solution ■ ■ ■<br />
When used as an adhesive agent for an indirect restoration, XP<br />
BOND does not need additional curing. The material will<br />
completely “dark cure” on its own even if parts of the bonding<br />
interface are not light cured.<br />
Self-etch, non-rinsing adhesives are also available to condition<br />
<strong>and</strong> prime enamel <strong>and</strong> dentin simultaneously without separate<br />
acid etching. Self-etching adhesives penetrate the smear layer<br />
<strong>and</strong> partially dissolve hydroxyapatite to generate the hybrid layer.<br />
One-bottle, self-etch adhesives such as Xeno® IV (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) are often regarded as more convenient <strong>and</strong><br />
less technique sensitive (Figures 1 through 4), as their application<br />
time is reduced compared to etch-<strong>and</strong>-rinse adhesives or<br />
two-bottle, self-etching systems. These adhesives do not require<br />
a moist dentin substrate because of the water inherent in their<br />
composition, <strong>and</strong> no etching is involved.<br />
The availability of adhesive systems that coincide with<br />
a clinician’s preferred bonding technique (Table) has thus<br />
simplified the delivery of direct resin restorations. Once the<br />
tooth surfaces are properly conditioned <strong>and</strong> the adhesive<br />
agent has been applied <strong>and</strong> cured, incremental layers of a<br />
universal composite such as Esthet•X® or TPH®3 (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) can be placed to achieve an aesthetic<br />
restoration with excellent physical properties <strong>and</strong> longevity.<br />
Consequently, concepts such as adhesive dentistry, aesthetics,<br />
<strong>and</strong> simplicity—once distant goals—can now be conducted<br />
in daily practice. ■<br />
30
› PRINCIPLES & PRACTICES<br />
Finishing <strong>and</strong> Polishing Composite<br />
Resin Restorations<br />
Clinical Parameters<br />
› Abstract:<br />
The use of composite resin<br />
restorations continues to<br />
increase as clinicians gain<br />
proficiency with state-ofthe-art<br />
dental materials<br />
<strong>and</strong> contemporary adhesive<br />
bonding techniques. In order<br />
to ensure optimal aesthetics<br />
in direct resin restoration,<br />
proper finishing <strong>and</strong> polishing<br />
procedures must be conducted.<br />
These clinical steps predispose<br />
the restoration for longterm<br />
performance <strong>and</strong> the<br />
patient for optimal oral health.<br />
Accordingly, selection of the<br />
appropriate instrumentation<br />
<strong>and</strong> use of sound operative<br />
principles as highlighted herein<br />
are imperative.<br />
Finishing <strong>and</strong> polishing composite<br />
resin requires a systematic<br />
approach to ensure an<br />
aesthetic outcome. Effective<br />
finishing <strong>and</strong> polishing of direct<br />
restorations is necessary not only for<br />
aesthetic purposes, but also to ensure optimum<br />
oral health. The accumulation <strong>and</strong><br />
retention of bacteria <strong>and</strong> plaque around<br />
composite restorations can be affected<br />
by the marginal finish, surface texture,<br />
<strong>and</strong> the integrity of the final restoration.<br />
If a smooth, well-polished surface is not<br />
achieved, this plaque accumulation can<br />
lead to chronic gingival inflammation,<br />
recurrent marginal decay, staining, <strong>and</strong><br />
restoration failure. The finishing <strong>and</strong> polishing<br />
of composite restorations also aids<br />
the clinician in establishing functional occlusion<br />
<strong>and</strong> contour. Devices for finishing<br />
<strong>and</strong> polishing include both cutting instruments<br />
(eg, multi-fluted carbide finishing<br />
burs) as well as abrasive finishing <strong>and</strong> polishing<br />
systems that will be used to successively<br />
refine restoration surfaces.<br />
Carbide burs are available in various<br />
sizes <strong>and</strong> utilized by the clinician to<br />
achieve natural tooth contours as well as<br />
to smooth restorative surfaces in advance<br />
of the polishing sequence:<br />
■ 12-fluted carbides—trimming <strong>and</strong><br />
contouring.<br />
■ 18-fluted carbides—successive finishing<br />
of surfaces.<br />
■ 30-fluted carbides—final finishing<br />
prior to polishing.<br />
Selection of the appropriate bur for a<br />
given clinical situation is dictated primarily<br />
by the required anatomy of the<br />
restoration. Embrasures, lingual regions,<br />
occlusal surfaces, <strong>and</strong> the various tooth<br />
shapes have differing contours that must<br />
be achieved during a finishing procedure.<br />
In this manner, longer shapes (eg,<br />
tapered, interproximal) are indicated for<br />
facial surfaces of anterior teeth or interproximal<br />
regions of canine <strong>and</strong> posterior<br />
teeth. Flame-shaped carbides are used for<br />
primary anatomy <strong>and</strong> round-end burs for<br />
contouring, whereas egg-shaped burs are<br />
Figure 1. Carbide fi nishing burs (Midwest ® Esthetic Finishing Burs,<br />
DENTSPLY Professional, York, PA) are ideal for refi ning margins <strong>and</strong><br />
obtaining optimal surface texture.<br />
Inset: The helical shape improves contact with the tooth surface.<br />
Figure 2. To provide a lasting surface luster with PoGo ® One Step<br />
Diamond Micro Polisher (DENTSPLY <strong>Caulk</strong>, Milford, DE), light pressure<br />
should be applied to the restoration surface.<br />
31
“Using PoGo saves me time <strong>and</strong> simplifies my<br />
polishing sequence. I find that PoGo can very<br />
efficiently <strong>and</strong> quickly render a great, glossy finish for<br />
my composite restorations.”<br />
Stephen Poss, DDS,<br />
Private practice, Brentwood, TN.<br />
A B A B<br />
Figure 3A. Preoperative view of fi lling that will be replaced with a direct<br />
resin restoration. 3B. After tooth preparation <strong>and</strong> adhesive bonding,<br />
TPH3 ® (DENTSPLY <strong>Caulk</strong>, Milford, DE) is layered.<br />
Figure 4A. Finishing is rendered using Enhance ® Finishers (DENTSPLY<br />
<strong>Caulk</strong>, Milford, DE) to enhance the appearance of the restoration. 4B.<br />
Final appearance of the direct resin restoration.<br />
geometrically well-suited to the lingual surfaces of anterior<br />
teeth (Figure 1). The helical blade geometry of the Esthetic<br />
Finishing Burs (DENTSPLY Professional, York, PA) aids in<br />
debris expulsion <strong>and</strong> diminishes chatter by maintaining<br />
broad contact with tooth surfaces. This produces a uniform<br />
finish conducive to efficient polishing. The wide assortment<br />
of designs, tapers, <strong>and</strong> blade lengths in the Midwest®<br />
Esthetic Finishing Bur portfolio ensures the clinician has a<br />
high-quality, efficient finishing instrument available for a<br />
given clinical need.<br />
The surfaces of a composite restoration can be further<br />
refined when finishing with carbide burs is followed by use<br />
of the Enhance® Finishing System <strong>and</strong> PoGo® One Step<br />
Diamond Micro Polishers (DENTSPLY <strong>Caulk</strong>, Milford, DE)<br />
(Figure 2). Aluminum oxide-impregnated finishing cups,<br />
discs, or points, as available in the Enhance® Finishing System,<br />
can deliver a finish that reduces the potential for biofilm<br />
formation <strong>and</strong> the risk of recurrent caries or staining (Figures<br />
3 <strong>and</strong> 4). To achieve an aesthetic, lustrous high polish, PoGo®<br />
One Step Diamond Micro Polishers can be applied with<br />
an increasingly light touch, resulting in a high-gloss shine,<br />
established line angles, <strong>and</strong> no alteration of form. Numerous<br />
in-vitro studies have confirmed that the one-step PoGo®<br />
system achieved the smoothest surfaces <strong>and</strong> highest gloss values<br />
in comparison to other polishing systems involving additional<br />
steps. 1-3 As a one-step polishing solution, PoGo® has<br />
also rendered resin restorations less susceptible to staining. 4<br />
Additional investigations establish the value of PoGo® for<br />
polishing microhybrid <strong>and</strong> nanoparticle resins to a highgloss,<br />
uniform appearance. 5<br />
As a properly finished composite restoration can influence<br />
its longevity, promoting greater wear resistance <strong>and</strong> marginal<br />
integrity, correctly instituting these procedures is essential.<br />
Using the DENTSPLY armamentarium as part of a cohesive<br />
finishing <strong>and</strong> polishing protocol st<strong>and</strong>s to extend the life of a<br />
resin restoration <strong>and</strong> to improve the efficiency of the clinician<br />
delivering it. ■<br />
References<br />
1. Yap AU, Yap SH, Teo CK, Ng JJ. Finishing/polishing of composite<br />
<strong>and</strong> compomer restoratives: Effectiveness of one-step systems.<br />
Oper Dent 2004;29(3):275-279.<br />
2. Da Costa J, Ferracane J, Paravina RD, et al. The effect of different<br />
polishing systems on surface roughness <strong>and</strong> gloss of various<br />
resin composites. J Esthet Restor Dent 2007;19(4):214-224.<br />
3. Ergücü Z, Türkün LS. Surface roughness of novel resin composites<br />
polished with one-step systems. Oper Dent 2007;32(2):<br />
185-192.<br />
4. Türkün LS, Leblebicioglu EA. Stain retention <strong>and</strong> surface characteristics<br />
of posterior composites polished by one-step systems.<br />
Am J Dent 2006;19(6):343-347.<br />
5. St-Georges AJ, Bolla M, Fortin D, et al. Surface finish produced<br />
on three resin composites by new polishing systems. Oper Dent<br />
2005;30(5):593-597.<br />
32