Abstract
Background: The effective bonding of fiber posts which are recommended in the restoration of endodontically treated teeth with excessive coronal damage is of critical importance for the long-term success. The aim of this study was to investigate the effect of various irrigation activation protocols on the push-out bond strength of fiber posts in different parts of the post space.
Methods: Forty-eight endodontically treated mandibular first premolar teeth were divided into 4 groups according to irrigation protocol (n=12): passive irrigation(PI); manual-dynamic irrigation(MDI); sonic irrigation(SI), ultrasonic irrigation(UI). Fiber posts were bonded with a self-adhesive resin cement. The roots were divided transversally into 3 sections as coronal, middle, and apical, in 2 mm each. Push-out bond strengths were calculated in MPa using a universal-testing machine. Each sample was examined under a stereomicroscope and failure types were classified as follows: adhesive failure between cement and dentin-Adhesive(C/D); adhesive failure between cement and fiber post-Adhesive(C/F); the combination of both adhesive failure types-mix.
Results: The lowest bond strength was obtained for PI(p<0.05). There was no statistically significant difference between the other groups (p>0.05). Coronal region showed significantly higher bond strength than the apical (p<0.05). While mixed failure was observed dominantly in the MDI, SI and UI groups, PI was the group that showed the adhesive(C/D) failure type in most.
Conclusion: After preparing the post space, using one of the irrigation activation protocols increased the bond strength of fiber posts.Regardless of the irrigation method applied, the bond strength of the fiber post was higher in the coronal region than the apical.