Effect of desensitizers on the microleakage of previously restored Class V resin composite restorations

Abstract

Objectives: The aim of this in vitro study was to evaluate the effect of different desensitizers' application on the microleakage of previously restored Class V composite resin restorations. Materials and methods: Class V cavities were prepared on the buccal surfaces of 40 extracted human third molars. Forty box-shaped cavities were divided into four groups, based on the desensitizers used (n = 10). All teeth were restored with the same bonding agent and composite material. No desensitizer was applied in the control group. In the experimental groups, BisBlock, Gluma and Universal bonding agents were the desensitizers. The desensitizers were applied after completion of composite restorations according to manufacturers' instructions. All specimens were then thermocycled at 5-55 degrees C, with a 10-s dwell time for 500 cycles. The samples were then immersed in 0.5% methylene blue dye for 24 h, sectioned into two equal halves, evaluated for microleakage using a stereomicroscope at 30x magnification and scored on a scale of 0-3. The data were analysed using the Kruskal-Wallis test at the significance level p < 0.05. Results: There were no significant differences in microleakage after desensitizer application (p > 0.05). However, based on the obtained numerical values in our study, while the BisBlock and bonding groups showed lower microleakage at the occlusal margin, BisBlock, Gluma and bonding group showed lower microleakage at the gingival margin compared to the control group. Conclusions: The application of desensitizers as a post-treatment option could be considered an advisable procedure to minimize microleakage.