Effect of Q-switched Er:YAG laser irradiation on bonding performance to dentin surface

The use of Q-switched erbium:yttrium-aluminum-garnet laser (Er:YAG laser), which have much less thermal effects than conventional Er:YAG lasers, has been proposed mainly in the medical field. The purpose of this study was to evaluate the bonding ability of dentin after Q-switched Er:YAG laser irradiation.The effects of dentin irradiation with Q-switched and conventional lasers were evaluated in terms of dentin morphology, roughness, hardness, elemental content, and resin bonding strength. Q-switched Er:YAG laser at average power densities of 20, 40, and 60 W/cm² and conventional Er:YAG laser at 909 W/cm² were used, and their performance was compared with that of the untreated group. Significant differences (p<0.05) were observed between 20 W/cm² and the other groups in term of surface roughness and surface hardness. The resin adhesion of the 20 W/cm² group was significantly higher than that of the other groups (p<0.05).