Push-Out Bond Strength of Fiber-Reinforced Post Using Various Post Space Irrigation Treatments

Objective: This study aims to provide the impact of different endodontic irrigation treatments after post space preparation on the push-out bond strength of fiber posts to dentin using self-adhesive cements. Methods and Materials: A total of 180 extracted premolar teeth were selected. The canals were instrumented by and then were filled. After preparing the post space, teeth were divided into 12 groups according to irrigants (normal saline solution; 17% EDTA [ethylenediaminetetraacetic acid] + 5.25% NaOCl [sodium hypochlorite]; 17% EDTA; 5.25% NaOCl; and 1.2% chlorhexidine [CHX]) and irrigation technique (conventional syringe irrigation [CSI] and passive ultrasonic irrigation [PUI]). After cementation, the samples were sectioned to obtain 1-mm disks from coronal and apical parts, a push-out test was performed using a universal testing machine (Z050, Zwick/Roell, Ulm, Germany) at a speed of 1 mm/min. The data were analyzed using one-way analysis of variance (ANOVA) and Mann-Whitney U tests. Results: The push-out bond strength was higher in coronal segment in comparison to apical segment. The highest push-out bond strength value was related to NaOCl + EDTA using PUI (12.39 ± 1.08). There are significant differences when comparing NaOCl + EDTA group with EDTA group using CSI or PUI technique (p  < 0.05) except in coronal region with CSI technique. In both apical and coronal regions, phosphoric acid irrigation was found to be similar to normal saline solution and CHX groups regardless of activation technique. Conclusion: The push-out bond strength values were significantly affected by the irrigation protocol. Using PUI and 17% EDTA + 5.25% NaOCl in apical region could be an effective irrigant for smear layer removal after post space preparation.