The Effect of Root Canal Cleansing on the Retention of Glass Fiber-reinforced Posts

Esthetic glass fiber-reinforced posts are being used more often. The most commonly reported complication associated with these posts is debonding. Dentine conditioning with solutions such as EDTA or MTAD results in removal of smear layer and might improve the retention of posts to root canal dentin. Therefore, the purpose of this study was to investigate the effect of cleansing the post space with MTAD or EDTA on the bond strength of glass fiber-reinforced posts, when cemented with self-adhesive resin cement. Forty-five (n=15) extracted human premolar teeth were sectioned at the cemento-enamel junction to obtain root length of fifteen millimeters. Endodontic instrumentation and obturation was performed. Post space was prepared to a length of ten millimeters. Post spaces were irrigated using one of two solutions: MTAD for five minutes and 17% EDTA for one minute. No irrigation was used in the control group. After irrigation, excess moisture was removed and posts were cemented with RelyX Unicem. Retention of posts was evaluated with pull-out test using universal testing machine (0.5 mm/min) to pull the posts from the teeth. Maximum load-to-failure was recorded. One-way analysis of variance was used for the statistical analysis (α=.05). Dislodged posts were examined at 8X magnification to determine the mode of failure. Mean bond strength (N) for the MTAD, EDTA and control group were 146.7, 142.8 and 151.4 respectively. The difference among the groups was not statistically significant (α>.05). Most dislodged posts exhibited mixed mode of failure. Based on these observations, it was concluded that the use of either EDTA or MTAD as a final rinse prior to post cementation does not influence the retention of glass fiber-reinforced posts, when cemented with self-adhesive resin cement.