Effect of Surface Conditioning and Resin Cements on the Adhesion of Fiber Posts

Purpose: This study evaluated the influence of surface treatments on the microtensile bond strength between a glass fiber post surface and resin cements. Methods: Forth-five posts (Reforpost, Angelus, Londrina, PRBrazil) were assigned to three groups with different surface treatment: Group 1: No treatment and silane application only (G1); Group 2: immersion in 96% ethyl alcohol for 10 minutes followed by silane application (G2); Group 3: immersion in 24% H2O2 for 10 minutes followed by silane application (G3). Each group was divided into 3 subgroups according to the resin cement used: UniCem/3MESPE (UN); BisCem/Bisco (BC); and Panavia F/Kuraray (PN). Posts were placed in a square-shaped matrix, in which it was held in place by the resin cement and subsequently photo-cured. Blocks were obtained, serially cut into sticks and then loaded onto a micro-tensile testing machine. Results: ANOVA indicated significant differences among surface treatments (p<0.05) and resin cements (p<0.05). The Tukey test revealed that the group G3 had greater bond strength than group G2 without a statistical difference (p>0.05). Group G1 had lower bond strength values (p<0.05). The values for group BC and group PN were significantly higher than group UN (p<0.05). The type of surface treatment and resin cement influenced the microtensile bond strength. Hypothesis: The use of different surface treatment can improve the chemical-mechanical interaction between fiber posts and resin cements, thus improving the performance of clinical application of these materials in endodontic treated teeth. Clinical Significance: Within the parameters of this study, the bonding capability of conventional and self-adhesive resin cements to fiber posts were affected by different post surface pre-treatments. Post surfaces treated with 24% H2O2 or 96% ethyl alcohol showed significantly stronger bond interactions to resin cements than only silane application.