Influence of Er:YAG laser on cavity preparation and surface treatment in microleakage of composite resin restorations

Objective: The purpose of this study was to assess microleakage on class V cavities prepared by Er:YAG laser with varying surface treatment. Background Data: There has been little reported research on microleakage at cavities prepared and treated with Er:YAG laser. Methods: Fifty preparations using Er:YAG laser or a highspeed handpiece were developed. The surface treatment was performed as follows: Er:YAG laser (group 1); 35% phosphoric acid (group 2); laser + acid (group 3); finishing with low-speed + laser + acid (group 4); conventional preparation developed with a high-speed handpiece + acid (group 5-control). The samples were restored with Single Bond/Z250, thermocycled, isolated, and immersed in a 50% AgNO3 solution. The restorations were sectioned, and the microleakage was, measured in milimeters using a specific computer software. Data were analyzed employing ANOVA and Tukey test. Results: Statistical analysis showed that group 5 (G5) obtained the lowest results of microleakage (22.05%), and it was statistically. similar (p > 0.05) to G1 (37.7%) and different (p < 0.05) from the other groups (G2 = 50.4%; G3 = 43%; G4 = 44.2%). The occlusal margins (22.62%) demonstrated less microleakage (p < 0.05) than the cervical margins (56.32%). Conclusion: The use of Er:YAG laser for cavity preparation and surface treatment negatively influenced the marginal sealing of composite resin restorations.