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), 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.