Bond strength of composite core build-up materials to fiber-reinforced posts: a microtensile comparison between conventional and wet-ethanol bonding systems.

PURPOSE: To evaluate the interfacial microtensile bond strength between a fiber-reinforced post (Rely X Post) and a core material (Multicore Flow) after placing different bonding agents. MATERIALS AND METHODS: After post surface treatment, 50 posts were divided into 5 groups. Group 1: Adper Prompt-L-Pop; group 2: SingleBond2; group 3: ScotchBond Multipurpose Plus; group 4: experimental bonding system (wet ethanol bonding technique); group 5: control group. After core reconstruction, the samples were tested with the microtensile test. Fracture type examination and SEM observation followed. Data were statistically analyzed with Kruskall-Wallis non-parametric ANOVA. RESULTS: Microtensile testing revealed significant differences (p < 0.001). There were no differences between groups 1 to 4, but there was a statistically significant difference between groups 1 to 4 and the control. Fracture type observations revealed more adhesive failures than cohesive or mixed ones. CONCLUSION: The experimental bonding technique did not improve bond strength compared to the different adhesive systems tested. However, placing a bonding agent between the post and the core seems to significantly increase microtensile bond strength.