Effect of dentin desensitizers on resin cement bond strengths

Resumo

The crown preparation promotes the exposure of dentin
tubules. Thus, to avoid post-operative sensitivity, the first approach
involves the use of dentin adhesives, and the second one the use of
dentin desensitizers. Objective: This study evaluated the effect of
dentin desensitizers on microtensile bond strengths (µTBSs) of a
resin cement to dentin. Material and methods: Twenty bovine teeth
were prepared until obtaining flat dentin surfaces. A standardized
smear layer was created (#600-grit SiC paper). The samples were
randomly divided into the following four groups (n = 5): no treatment
(Control), treatment with Gluma Desensitizer (Heraeus Kulzer), Super
Seal (Phoenix Dental) and Teethmate Desensitizer (Kuraray Noritake
Dental). The dentin surfaces were then treated with ED Primer II
(Kuraray Noritake Dental). Twenty composite blocks, 4 mm thick
(Estenia C&B, Kuraray Noritake Dental) were used. The composite
surfaces were abraded with aluminum oxide (50 µm), and then
silanized. The composite block was bonded to the dentin surface with
a resin cement (Panavia F 2.0, Kuraray Noritake Dental) according to
the manufacturer’s instructions. After 24-hour storage (37ºC, 100%
RH), the bonded samples were cut into beam–shaped microtensile
specimens and loaded in tension until failure. Data were analyzed
with one-way ANOVA and the Dunnett’s test (α = 0.05). An SEM was
used to examine the failure modes. Results: The µTBSs (MPa ± SD)
were: 24.4 ± 3.2 (Control), 14.0 ± 5.6 (Gluma Desensitizer), 8.6 ±
4.7 (Super Seal), and 34.7 ± 4.6 (Teethmate Desensitizer), in which
there were significant differences among the four groups (p < 0.05).
The Teethmate Desensitizer group showed the highest µTBS, while
the Super Seal group showed the lowest mean of µTBS to dentin.
Conclusion: The efficacy of the desensitizers is material-dependent;
Gluma Desensitizer and Super Seal decreased the µTBSs, however,
Teethmate Desensitizer improved it.