The effect of different surface treatments on the bond strength of composite resin core to carbon fiber posts

Carbon fiber posts are widely used in dentistry. The most problem is their low bond strength with composite resin utilized as core. The aim of this study was to evaluate the effect of different surface treatments on the tensile bond strength of composite resin core to carbon fiber posts. Methods & Materials: Thirty six posts free of defects, were selected and randomly divided into 4 groups and treated as follows: Group1: No treatment (control). Group2: Surface treatment with Single Bond Group3: Surface treatment with Sandblast + Single Bond Group4: Surface treatment with Sandblast + Silane + Single Bond. A cylindrical composite resin core (5×5×5 mm) was built around each post using Z100. Post-core assemblies were tested for tensile failure by Instron testing machine at a cross-head speed of 10 mm/min. The bond strength was assessed by Newton (N). The tensile bond strength were respectively, Group 1: 262.33± 23.37N, Group 2: 522.77± 37.33N, Group 3: 613.50± 39.93N, Group 4: 641.00± 43.35N. ANOVA and Scheffe test showed that group 1was the least retentive group of all (p<0.05), and group 3 and group 4 were significantly more retentive than group 2 (p<0.05).There was no significant difference between group 3 and group 4. The surface treatment of carbon fiber posts significantly improved their retention to composite resin.