Can cement film thickness influence bond strength and fracture resistance of fiber reinforced composite posts?

Objectives This study compared the influence of cement film thickness (CFT) on bond strength (BS) and fracture resistance (FR) of fiber-reinforced composite (FRC) posts to root canal. Materials and methods One hundred bovine incisors were used for BS and FR analysis ( n = 10) and distributed into five experimental groups according to FRC post diameters (WhitePost DC no. 0.5, no. 1, no. 2, no. 3, no. 4), leading to five different CFTs. The canals were prepared using drill no. 4 provided by the post manufacturer and irrigated with 2.5 % NaOCl. After conditioning (24 % H 2 O 2 /5 min) and silanization, posts were cemented with resin cement. BS was evaluated using push-out test and FR using the compression test at 45°. A stereomicroscope was used to measure CFT and to analyze failure pattern. BS data were subjected to two-way ANOVA and Scheffé test for contrast ( α = 0.05); FR data were subjected to one-way ANOVA. Results BS was significantly affected by CFT, as the most well-adapted post achieved the highest values ( p