THE JOURNAL OF - Dentsply

XP BOND in Self-curing Mode used for Luting Porcelain
Restorations. Part A: Microtensile Test
Ornella Raffaelli a /Maria Crysanti Cagidiaco b /Cecilia Goracci c /Marco Ferrari d
Purpose: To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cement used
in different curing modes to lute ceramic disks of different thicknesses.
Materials and Methods: Empress II disks (Ivoclar-Vivadent) were luted to dentin using XP BOND (Dentsply [XP]) in
combination with the proprietary self-curing activator (SCA) and cement Calibra (Dentsply [C]). Curing of the adhesive
was induced either by mixing with the activator (activator, groups 3 to 6) or by light irradiation for 20 s (group 2). The
cement was either light cured for 40 s through the ceramic onlay (groups 1 to 5) or cured chemically (groups 6 and 7).
Groups 2 and 4 were compared with group 1, in which Prime & Bond NT (Dentsply DeTrey) was tested as control. In
groups 3 and 6, 2-mm-thick onlays were luted with XP+SCA, and the cement was light cured for 40 s or let autocure for
5 min, respectively. These groups were compared with group 7, in which Syntac (Ivoclar Vivadent) was applied with C
and, in order to reproduce the handling procedures of group 6 (although contrary to manufacturer’s instructions), no
light irradiation was provided for the adhesive or the cement. The influence of onlay thickness (2, 3, 4 mm) on the
bond strength developed by XP+SCA/C was assessed by comparing groups 3, 4, 5. In these groups, C was light cured
for 40 s through the onlay. Microtensile beams were obtained from the luted teeth.
Results: Bond strengths not including pretest failures (in parentheses: value including pretest failures as 0 MPa) were
21.0 (17.5) MPa in group 1, 24.9 (21.2) MPa in group 2, 23.7 (21.3) MPa in group 3, 29.9 (26.7) MPa in group 4, 30.3
(24.6) MPa in group 5, 28.6 (24.6) MPa in group 6, and 17.1 (9.2) MPa in group 7. Statistically significant differences
were found between groups 1 and 4, groups 3 and 5, and groups 6 and 7.
Conclusion: The bonding potential of XP BOND used with the activator or light cured in combination with Calibra in
self- or dual-curing mode outperformed that of a control adhesive-cement system. The bond strength of XP+ SCA + Calibra
was not negatively affected by the onlay thickness.
J Adhes Dent 2007; 9: 275-278. Submitted for publication: 15.12.06; accepted for publication: 5.1.07.
a PhD Student, Department of Dental Materials and Prosthodontics, University of
Siena, Siena, Italy.
b Clinical Professor of Dentistry, Department of Dental Materials and Prosthodontics,
University of Siena, Siena, Italy.
c Assistant Professor and Chair, Department of Endodontics, University of Siena,
Siena, Italy.
d Professor and Chair, Department of Dental Materials and Prosthodontics, University
of Siena, Siena, Italy.
Paper presented at Satellite Symposium on Dental Adhesives, Dublin,
September 13th, 2006.
Reprint requests: Prof. Marco Ferrari, Research Center for Dental Health, 19 Piazza
Attias, 57120 Livorno, Italy. Tel: +39-586-892-283, Fax: +39-586-898-305.
e-mail: ferrarimar@unisi.it
Many new bonding systems are introduced every year on
the market. Some of them are primer-adhesive solutions
in combination with a prior phosphoric acid treatment,
others avoid the total-etch step and offer self-etching or selfadhesive
bonding solutions. 3,5,7-10
However, practitioners would like to use the same bonding
systems for all clinical applications, although most simplified
bonding solutions are not necessarily indicated for
luting indirect restorations, limiting their clinical indications
to direct restorations.
Recently, XP BOND (Dentsply DeTrey; Konstanz, Germany),
using tert-butanol for the first time as solvent in dentistry,
was proposed as a one-bottle universal adhesive, also
in combination with a new self-curing activator (SCA).
When luting a porcelain restoration, differences in thickness
may reduce the light penetration, resulting in a reduced
polymerization rate of the luting material. 1,2,4 To avoid
an incomplete cure of the resin cement adhesive interface,
the self-curing activator can be used.
Consequently, the aims of this study were to evaluate (1)
the procedure for adhesively luting ceramic to dentin and,
specifically, when light is applied, to cure either the adhesive
before or after applying the cement, (2) the influence of ceramic
thickness when the adhesive is not separately light
cured but mixed with a self-curing activator (SCA), (3) the influence
of SCA on the bonding efficacy when no light is
used. The null hypothesis tested is that differences in porcelain
thickness and curing mode do not affect the bond
strength values.
Vol 9, Supplement 2, 2007 275