Effect of dentin desensitizers on resin cement bond strengths

Introduction: 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 he 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