Effect of Er: YAG laser dentin pretreatment on composite bonding: a systematic review and meta-analysis

This review aims to systematically evaluate the effect of Er: YAG laser dentin pretreatment on the shear bond strength (SBS) of composite resin, by comparing it with conventional mechanical caries removal and etch-and-rinse techniques. Two researchers independently searched in PubMed, Web of Science, Cochrane Library, and EMBASE for literature (January 2020-December 2024), identifying 13 in vitro studies. A meta-analysis (95% confidence interval) was then conducted using RevMan 5.3. While Er: YAG laser showed comparable SBS to mechanical preparation (P = 0.05), it underperformed etch-and-rinse (P < 0.00001). Er: YAG laser pretreatment increased SBS by 4.46 MPa compared to untreated dentin (P < 0.00001). Notably, a statistically significant enhancement in SBS was noted when combining Er: YAG laser with etch-and-rinse, significantly enhancing SBS over laser treatment alone (P < 0.00001). High heterogeneity (I²>50%) was attributed to variations in parameter settings of Er: YAG laser, types of samples (primary/permanent teeth), and diversity of adhesive systems. Er: YAG laser can achieve equivalent SBS with conventional mechanical tooth preparation, but underperforms etch-and-rinse when used alone. Combinational application with etch-and-rinse significantly improves bonding performance without markedly influencing bonding failure modes. This conclusion is limited by high heterogeneity and in vitro study designs.