Bond Strength of Resin Composites used as Core Materials around Different Types of Fiber Posts

The purpose of this study was to evaluate the shear bond strength of two resin composites around different types of fiber posts. Twenty post specimens were prepared for three types of fiber posts. Posts were embedded in acrylic resin blocks with half of the post diameter exposed. The exposed portions of the posts were successively ground with silicon carbide paper until flattened flush with the acrylic resin, to create a standard smooth surface. All the posts were treated with a single silane coupling agent layer. After silane application, the posts were gently air dried. Three types of fiber posts were randomly divided into two groups, according to the resin composite used. The light-cured composite resins were placed in a polytetrafluoroethylene mold positioned over the post specimens and they were polymerized. Shear bond strength values (MPa) of posts and composite resin cores were measured using an universal test machine. Twoway analysis of variance (ANOVA) and Tukey’s test were used for statistical analysis. The result of two-way ANOVA showed that the difference between the post groups was not significant (p = 0.59). But significant differences were observed between the core materials (p = 0.018). The shear bond strength values were not affected by the type of the fiber post. The type of the composite core material affected the bond strength values between the fiber post and composite core.