Abstract:Objective:To investigate the effect of Er:YAG laser and/or acid-etching pretreatment on the bond strength of self-adhesive resin cement. Methods:Forty-four extracted human premolars were randomly divided into 4 groups according to the different pretreatment on the dentin surface:Control group,Er:YAG laser group,acid-etching group,and Er:YAG laser+acid-etching group. One tooth selected randomly from each group was cut into 3 mm dentin slices,then observed under Scanning electron microscopy (SEM) after pretreatment. The remaining ten teeth were prepared into the consistent standards dentin surface,then bonded with the self-adhesive resin cement RelyXTM Unicem and Everest ZS zirconia ceramic after pretreatment,tested shear bond strength after 24 h. Results: SEM showed the differences of dentin surface morphology pretreated by different methods. The results of statistical analysis showed that the shear bond strength in the order from high to low is Er:YAG laser group (7.18 ± 2.54MPa),Er:YAG laser with acid-etching group(5.50 ± 2.09MPa),Control goup(4.05 ± 1.04MPa),and Acid-etching group (3.61 ± 0.70MPa);there was a significant difference between Er:YAG laser group,Er:YAG laser with acid-etching group and Control goup (P < 0.05),however,there was no significant difference between Acid-etching group and Control goup(P > 0.05). Conclusion: The study shows that the influence of acid-etching on the shear bond strength of self-adhesive resin is not obvious,while Er:YAG laser pretreatment can obtain better dentin bonding surface,and improve the shear bond strength of the self-adhesive resin with dentin and zirconia ceramic。