Effect Of Different Resin Cements And Silane Coupling Agents On Bond Strength Of Glass Fiber Post To Root Dentin

Objective: To evaluate the influence of different resin cements and silane coupling agents on bond strength of glass fiber posts to root dentin.Methods: Twenty-four sound human incisors of similar size extracted recently were selected. The coronal portions of each tooth were removed with a diamond bur at 1-mm coronal to the cemento-enamel junction (CEJ). After endodontic treatment (gutta-percha points and calcium hydroxide cataplasm), the root canal preparation was performed with the canal drill provided by the manufacturer to a depth of 12 mm from the CEJ. Twenty-four MATCHPOST glass fiber posts were immersed into 24% hydrogen peroxide for 10 min and coated silane coupling agents, and cemented to the root canals prepared. According to the different silane coupling agent, 24 teeth root were randomly divided into two equal main groups of 12 each: A group (two components silane coupling agent) and B group (single component silane coupling agent). Teeth root from the two main groups were randomly distributed into there equal subgroups according to different resin cement: RU group (RelyX Unicem self-adhesive system); PF group (Panavia-F self-etching system) and DL group (DUO-LINK total-etching system). After storage in room temperature for 24 hours, each root embedded vertically in the PVC tube with self-curing resin was cut perpendicular to the long axis with low speed diamond saw to obtain 3 slices with 3.0-mm-thick as test specimens. Specimens of each test group (n=12) were loaded in an universal testing machine at a cross-head speed of 1.0 mm/min until failure occurred. The dates obtained were submitted to the two-way ANOVA and multiple comparison (α=0.05) by the SPSS V13.0. Failure mode of each specimens were observed and recorded. Results: Bond strength values (MPa) of six test groups from the highest to the lowest were as follows: B-RU (14.8±5.17); B-PF (9.77±4.77); A-RU (9.42±4.93); A-PF (8.69±3.40); B-DL (5.71±2.71); A-DL (5.22±1.69). Two-way ANOVA revealed that silane coupling agent (p=0.014) and resin cement (p=0.000) significantly effected bond strength, whereas the interaction between these two factors was not significant (p=0.079). Further analysis with post-hoc test revealed that significant differences (p<0.05)could be found between every two groups of three (RU, PF and DL).Conclusion: Within the limitations of this in vitro study, the following conclusions were drawn:1. Different resin cements and silane coupling agents significantly influenced bond strength of glass fiber post to root dentin.2. Bonding effects were significant differences among the three adhesive resin cements. Self-adhesive resin cement (RU) showed the better bond strength than self-etching (DL) and total-etching (PF).3. One-component silane coupling agent should be recommended in clinical.