Effect of customisation, root canal reshaping and acid etching on push-out bond strength of fiber post in flared, MTA repaired root canal

Clinicians routinely encounter the endodontically treated teeth with wide flared canals and mineral trioxide aggregate (MTA) repair on the canal wall.To assess the effect of customized glass reinforced composite (FRC) post and reshaped root canal along with different acid etching protocol of MTA surface on push-out bond strength (PBS) in flared, MTA repaired root canal.Ninety recently extracted single-rooted premolar teeth were sequentially subjected to root canal obturation, post space preparation, flaring, and MTA application. The samples were randomly divided into 3 groups of control (no relining or reshaping), customized FRC post by relining with self-adhesive resin cement and reshaping the canal with flowable composite. Each group was subdivided into 3 subgroups (n= 10) as no surface treatment, 37% H3PO4 and 19% EDTA etching of MTA surface. Teeth samples cemented with FRC post were sectioned into 2 mm and push-out testing.Control group had the lowest PBS at 1.988 N. The PBS values for the groups with customized post relining were 8.489 N, 8.888 N and 7.911 N for control, H3PO4 etch and EDTA etch. The corresponding PBS values for root canal reshaping were 7.323 N, 8.318 N and 7.785 N.Customized FRC post with 37% H3PO4 etching is advised for the flared and MTA repaired root canals.