Fracture resistance of teeth restored with or without FRC post

Objectives: To compare the effect of the novel fibre reinforced composite post (FRC) and resin composite core build up on fracture resistance and mode of failure of endodontically treated teeth Methods: Twelve human premolar with a single root were divided into 2 groups according to the type of restorations: Group 1 - no FRC post, only composite core (Multicore flow®, Ivoclar Vivadent, Liechenstein); Group 2 - FRC post (FRC postec Plus No.1, Ivoclar Vivadent, Liechenstein) and composite core (Multicore flow®). All teeth were prepared with circumferential shoulder including 2 mm ferrule; then applying adhesive agent (Excite DSC, Ivoclar Vivadent, Liechenstein) and using composite resin core build up. The sample was tested in compression mode of universal testing machine (Instron 5566, UK) with cross head speed of 1mm/min and the fracture resistance was evaluated. The Mann-Whitney U test was used to compare the fracture load among experimental groups with a significant level of p <0.05. Results: The median fracture load for group 1 and 2 were 853(249.43) N and 709.45 (198.06) N respectively. No significant differences were detected among the groups. The fracture analysis indicated the cohesive failure within the FRC post and composite core build up closed to apical one third of root canal. Conclusions: Under this test condition, the restoration for endodontically treated teeth with only composite core build up showed the promising fracture strength to that with FRC post.