关键词: Er:YAG激光, 酸蚀, 牙釉质, 剪切粘结强度

Abstract: Objective: To investigate the influence of Er:YAG laser treatment on the characteristics of enamel surface and the bonding strength of resin. Methods: Fifty human premolars and molars without any caries and fillings were collected and eighty-four mesiodistal sections of the teeth were selected.The specimens were randomly divided into 7 groups(Group A-G) based on the different surface treatments (n=12).Two specimens in each group were randomly chosen and observed by scanning electron microscope (SEM). The other ten specimens in each group were bonded to the light-cured composite resin and the shear bond strength (SBS) were tested. Results: The highest SBS value of Group A was 20.51±3.33Mpa.The values of Group B,C and D were lower than that of Group A.However,the difference between these four groups was not statistically significant. The values of Group E,F and G were lower than those of other four groups.The differences between Group F and G and the other five groups were statistically significant. There was no significant difference between Group E and Group B,C and D. The SEM results showed that the surface roughness of enamel increased with the enhancement of laser energy.When the specimens were etched by acid after laser treatment process, the structure of enamel surface became uniform without smear layer and the structure of the enamel column was clearly visible. Conclusion: The Er:YAG erosion of enamel surface could not achieve a similar result as acid etching. The enamel surface treated by laser combined with etching could achieve similar effect with acid etching. The SBS results were increased with the increasing of laser energy.

Key words: Er:YAG, laser, Acid, etching, Enamel, Shear, bond, strength