Oval versus circular-shaped root canals: Bond strength reached with varying post techniques

• Main Authors: Amaral, F.L.B (Author), Basting, R.T (Author), Bernardon, P. (Author), França, F.M.G (Author), Turssi, C.P (Author), Webber, M.B.F (Author)
• Format: Article
• Language: English
• Published: Associacao Brasileira de Divulgacao Cientifica 2018
• Subjects: anatomy and histology; Bicuspid; Bond strength; Canal cross-section shape; chemistry; dental bonding; Dental Bonding; Dental Cements; dental procedure; dental pulp cavity; Dental Pulp Cavity; Dental Stress Analysis; endodontic procedure; glass; Glass; glass fiber; Glass fiber post; human; Humans; in vitro study; In Vitro Techniques; Intraradicular dentin; Post and Core Technique; Post technique; premolar tooth; procedures; resin cement; Resin Cements; Root Canal Therapy; tooth cement; tooth crown
• Online Access: View Fulltext in Publisher

 The aim of this study was to compare the bond strength (BS) of glass fiber posts (GFP) luted to oval and circular-shaped root canals rehabilitated using varying post techniques, at different intraradicular levels. Ninety 16-mm-long roots of human mandibular premolars, classified either as having oval or circular-shaped canals, were endodontically treated and prepared for restoration using one of three different post techniques (n=15): 1) single GFP; 2) resin-relined GFP; 3) main GFP associated with accessory posts. GFPs were luted with a dual polymerizing resin cement (RelyX ARC) after the canal had been treated with a 3-step etch-and-rinse adhesive system (Adper Scothbond Multipurpose). The samples were sectioned into three 1-mm-thick sections, which were differentiated by the root level (cervical, middle and apical) and tested for push-out BS. Assessment of failure mode was made under a stereomicroscope. Data were analyzed using repeated measures three-way ANOVA and Tukey’s test. The root canal cross-section had a significant influence on BS (p<0.001), with the lowest values being observed in oval-shaped canals. The post technique also significantly affected the BS (p=0.018), with the resin-relined GFPs providing the highest BS values in both oval and circular-shaped canals. Irrespective of the cross-section of the root canal and post technique, there was no significant difference in BS in the cervical, middle and apical third of the root canal (p=0.084). In oval-shaped canals, the BS to intraradicular dentin at cervical, middle or apical level could be increased when the GFPs posts were relined. © 2018, Associacao Brasileira de Divulgacao Cientifica. All rights reserved.