Benefits of a Two-step Cementation Procedure for Prefabricated Fiber Posts

Purpose: To determine whether two-step cementation of prefabricated fiber posts leads to higher bond strengths. Materials and Methods: Forty-eight human canine teeth were divided into six groups and fiber posts were cemented with DC Core, RelyX Unicem and Panavia F2.0, according to a one-step or two-step procedure. Per root, four cross-sections were prepared. The differences in push-out strength between procedure, cement and location within the root were determined. Results: For all cements, the push-out strengths for the two-step procedure were significantly higher than for the onestep procedure (p 0.001). Differences between the cements for both the one-step and two-step procedure were not statistically significant (p = 0.05). Conclusion: The reduction of the C-factor by means of a two-step cementation, a procedure equivalent to the layering technique of composite restorations, resulted in significantly higher bond strengths. The increase of 60% in bond strength may be beneficial to the retention of post and core restorations. Schlagwörter: prefabricated fiber post, cementation procedure, C-factor, push-out strength, polymerization shrinkage