Shear bond strength and SEM evaluation of composite bonded to Er:YAG laser-prepared dentin and enamel

Objectives. The purpose of this study was to evaluate dentin and enamel bond strength to resin composite following high-speed rotary or Er:YAG laser preparation using a total etch adhesive system. The microstructure of resin–tooth interfaces was also investigated. Methods. Human dentin and enamel specimens were prepared with a high-speed handpiece (KaVo) or Er:YAG laser (DELight) at manufacturer's recommended settings and etched with either 37% H 3PO 4, laser etched, or not etched. Composite rods (Z-250, 3M/ESPE) were bonded to specimens with an adhesive (Adper Scotchbond Multi-Purpose, 3M/ESPE). After thermocycling, specimens were tested in shear to failure. Results. Two-factor ANOVA detected significant differences in the main effects of preparation and etch type, and interaction ( p