[Marginal microleakage of cavities prepared with Er:YAG laser on primary teeth in vitro].

OBJECTIVE: To investigate the marginal microleakage after cavity preparation by Er:YAG laser and conventional bur applying different adhesive systems, conditioning surface with acid etching or not. METHODS: In the study, 50 primary teeth were divided into 5 groups. (1) Bur + etch-and-rinse system, (2) Bur + self-etching system, (3) Er:YAG laser + etch-and-rinse system, (4) Er:YAG laser + self-etching system, (5) Er:YAG laser + none-etched. The class V cavities were all filled with composite resin. The microleakage tests were performed, observed and scored under stereomicroscope. RESULTS: Bur + etch-and-rinse group had higher microleakage than Er:YAG laser+etch-and-rinse group, and Bur+self-etching group had higher microleakage than Er:YAG laser + self-etching group(P<0.05). There was no difference between Er:YAG laser + etch-and-rinse group and Er:YAG laser + self-etching group, while they had significantly lower microleakage than that of Er:YAG + none-etched group. CONCLUSION: Composite resin restoration showed less marginal microleakage when all-in-one self-etch system was used after irradiation by Er:YAG laser on primary teeth.