Abstract: Objective To investigate the influence of different silanization treatments on the shear bond strength of fiber posts and the SEM structure. Methods 20 glass fiber posts were divided into 4 groups（n=5）: no treatment(A), chair-side silane application(B), industrial silane treatment(C), industrial silane treatment followed by chair-side silane application(D). After surface treatment, a composite resin core was placed around each fiber post by a PTFE tube. The specimens were embedded in a cylinder of clear self-cured acrylic resin and sectioned into 1-mm-thick segments with a water-cooled diamond blade. Each post can be sectioned into 10 segments. In each group, 5 segments were put under the SEM to observe the ultra microstructure of the bonding interface of the fiber post and the resin core material and 45 other segments were put onto a universal testing machine and micro push-out tests were performed at a crosshead speed of 0.5 mm/min. The data were recorded and analyzed statistically (α=0.05). Results The mean shear bond strengths achieved in each group were （13.46±1.78）、（18.39±1.60）、（24.54±1.34）、（24.39±1.65）MPa. The treatment groups showed higher shear bond strengths than that of the control group(A) (P＜0.001). Group C showed higher bond strengths than Group B (P＜0.001). No significant difference was found between the group C and group D. No defects were detectable at the interface of fiber posts and resin core materials in all the groups. In Group C and group D, microretentive morphological changes were observed. Conclusion Within the limitations of this study, industrial silane treatment can enhance the shear bond strength of fiber posts. SEM analysis reveals the presence of microretentive morphological changes, which can certainly increase post-retentive properties.

Key words: silanization, fiber post, scanning electron microscope ( SEM), bonding interface, micromorphology