Assessing microleakage of composite restorations in class V cavities prepared by Er:YAG laser irradiation or diamond bur

The aim of this study was to make a comparison between microleakage of conventionally restored class V cavities using bur and acid etchant and, the ones prepared and conditioned by Er:YAG laser. 30 recently extracted intact caries and filling free human permanent molars were used for this study. Then, Cold cure acrylic resin was used to seal the apices. The samples were randomly assigned to 5 groups of six each. Class V cavities were prepared one on buccal and one on lingual surface of each sample. Group 1: cavity preparation by diamond bur and turbine + acid etch, Group 2: cavity preparation by Er:YAG laser + acid etch, Group 3: cavity preparation by Er:YAG laser + Laser etching, Group 4: cavity preparation by diamond bur and turbine + laser etching, Group 5: cavity preparation by Er:YAG laser with no conditioning procedure. The cavities restored with restorative composite resin. Samples were then immersed in 2% methylene blue solution for 24 hours. The data were then analyzed using Wilcoxon signed ranks test and Kruskal-Wallis statistical tests. The Kruskal Wallis test showed a significant difference (P < 0.05) between enamel and cementum margin microleakage, while the higher microleakage was related to the cementum margin of restorations. There was no significant difference in evaluating microleakeage degree of cavities prepared by Er:YAG laser and diamond bur.