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

Abstract 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, ۳۰ fiber posts (Glassix, Nordin, Switzerland) were randomly divided into ۵ groups of sandblasting, no treatment and laser irradiation at ۱, ۱.۵ and ۲ W powers. Following composite filling and mounting, ۱-mm thick sections were made for push-out bond strength testing. Half of the samples in each group were subjected to thermocycling (n=۱۵). Two-way analysis of variance (ANOVA) was used to analyze the bond strength values. Pairwise comparisons were made using Tukey test (P < ۰.۰۵).Results: Effect of treatment method on push-out bond strength of fiber post to composite core was significant (P = ۰.۰۱۷), while thermocycling had no significant effect on bond strength (P = ۰.۹۶۴). Pairwise comparison of surface treatment methods revealed no significant difference in groups with and without thermocycling (P > ۰.۰۵), but Er,Cr:YSGG laser irradiation with ۱ W power yielded significantly higher bond strength than the control group (P =۰.۰۱).Conclusion: Irradiation of Er,Cr:YSGG laser at ۱ W power increased the bond strength of fiber post to composite core. Thermocycling slightly decreased the bond strength at the fiber post-core interface. Keywords: Bond strength Composite Er Cr YSGG laser Post.