Oval Versus Circular-Shaped Root Canals: Bond Strength Reached with Varying Post Techniques

• Published in: Brazilian dental journal Vol. 29; no. 4; p. 335
• Main Authors: Webber, Mariana Benedetti Ferreira, Bernardon, Paula, França, Fabiana M G, Amaral, Flávia L B, Basting, Roberta T, Turssi, Cecilia Pedroso
• Format: Journal Article
• Language: English
• Published: Brazil 01.07.2018
• Subjects: Bicuspid; Dental Bonding - methods; Dental Cements; Dental Pulp Cavity - anatomy & histology; Dental Stress Analysis; Glass; Humans; In Vitro Techniques; Post and Core Technique; Resin Cements - chemistry; Root Canal Therapy - methods
• ISSN: 1806-4760

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.