Endodontic Sealers Affect the Bond Strength of Fiber Posts and the Degree of Conversion of Two Resin Cements

Purpose: To evaluate the effect of two endodontic sealers on the push-out bond strength between fiber posts and root canal wall after different storage times and verify the influence of the endodontic sealers on the degree of conversion of composite cements. Materials and Methods: A total of 180 bovine teeth were endodontically treated using two endodontic sealers, eugenol-based (Endofill, Dentsply Maillefer) or epoxy resin-based (AH Plus, Dentsply Maillefer). Subsequently, the specimens were stored in 100% relative humidity at 37°C for 24 h, 6 or 12 months. After the respective storage times, the root canals were prepared for fiber post cementation using two composite cements, RelyX U200 (3M) or Multilink Automix (Ivoclar Vivadent). The push-out test and the failure analysis were performed. Degree of conversion was analyzed using a Raman microscope, for which samples were prepared using composite cement only or composite cement plus endodontic sealer. Finally, the push-out data were subjected to statistical analysis and the degree of conversion in percent was calculated. Results: AH Plus sealer obtained the highest push-out bond strengths at 24 h and 6 months. There was no difference between the push-out bond strengths of AH Plus and Endofill sealer at 1 year (p 0.05). Moreover, the degree of conversion was affected by the Endofill sealer. Conclusion: The use of a eugenol-based sealer is not recommended because it affects the push-out bond strength of fiber posts. AH Plus sealer and a post-endodontic waiting time of 24 h is recommended. Schlagwörter: degree of conversion, endodontic sealer, eugenol, fiber post, push-out bond strength test