Effect of Sonic Application on Push-out Bond Strength of Fiber Posts to Root Canal Dentin

Abstract

The purpose of this study was to evaluate the effect of a sonic application on the push-out bond strength of fiber posts to root canal dentin when luting with self-adhesive resin cement and resin composite core material. Twenty single root canal mandibular premolars were endodontically treated and randomly divided into four groups according to the cementation materials and post insertion techniques; RelyX Unicem/conventional technique, RelyX Unicem/sonic application, Multicore flow/conventional technique, Multicore flow/sonic application. After post cementation and 24 hour-storage, the roots were sectioned into six slides (two-coronal, two-middle, two-apical region) and the push-out test was performed by a universal testing machine. The failure mode was evaluated by stereoscopic microscope and the bonded interface of representative specimens were observed using scanning electron microscope. The results revealed that sonic application did not affect the push-out bond strength of the fiber post but tended to yield better results in the resin composite core material group. The resin cement showed a significant higher bond strength, irrespective of the mode of application. Regional factor affected the bond strength only in resin cement group. There was a predominance of adhesive failure in all groups. Conclusion, the sonic application did not significantly improve the adhesion to the fiber post. Luting fiber post with resin cement provided the better result compared to resin composite core material.