Effect of Different Surface Treatments on Push-out Bond Strength of Glass Fiber Posts to Resin Composite Core Material

The aim of this study was to evaluate the effects of surface pretreatments of fiber-reinforced post on thin-slice puch-out bond strength to resin composite core material. Prefabricated glass fiber posts Parapost 1.4 mm diameter were divided into four groups; Group C: no pretreatment, Group A: air abraded using110 μm aluminum oxide, Group PH: phosphoric acid immersion, and group H: hydrogen peroxide immersion. Each group was then subdivided into two subgroups; Subgroup A: Silane coupling agent (EspeSil, 3M Espe) and Subgroup B: ONESTEP adhesive system (ExciTE F DSC, Ivoclar Vivadent) applied to the treated post surfaces. A flowable dual-cured resin composite core material (Multicore Flow, Ivoclar Vivadent) was applied to each group for testing the adhesion using thin-slice push-out test. Data were analyzed using two-way ANOVA. The highest bond strengths was observed for H2O2 group after treatment with silane coupling agent (18.1± 2.3 MPa) followed by air abraded group (14.3 ± 1.8 MPa). The lowest bond strength was observed for phosphoric acid etching groups for both silane and adhesive treated subgroups (11.3 ± 1.6 MPa & 12.4 ± 1.9 MPa). When comparing bond strength (MPa) values dependent on the type of bonding used (silane vs. bonding), analysis of variance demonstrated no statistically significant differences (p<0.05).