Bond Strength of Fiber Posts to Composite Core: Effect of Surface Treatment With Er,Cr:YSGG Laser and Thermocycling

Introduction: this study aimed to determine the bond strength of fiber post to composite core following surface treatment with er,cr:ysgg laser at different powers and sandblasting with and without thermocycling. methods: in this experimental study, 30 fiber posts (glassix, nordin, switzerland) were randomly divided into 5 groups of sandblasting, no treatment and laser irradiation at 1, 1.5 and 2 w powers. following composite filling and mounting, 1-mm thick sections were made for push-out bond strength testing. half of the samples in each group were subjected to thermocycling (n=15). two- way analysis of variance (anova) was used to analyze the bond strength values. pairwise comparisons were made using tukey test (p < 0.05). results: effect of treatment method on push-out bond strength of fiber post to composite core was significant (p = 0.017), while thermocycling had no significant effect on bond strength (p = 0.964). pairwise comparison of surface treatment methods revealed no significant difference in groups with and without thermocycling (p > 0.05), but er,cr:ysgg laser irradiation with 1 w power yielded significantly higher bond strength than the control group (p =0.01). conclusion: irradiation of er,cr:ysgg laser at 1 w power increased the bond strength of fiber post to composite core. thermocycling slightly decreased the bond strength at the fiber post-core interface.