Effect of intraradicular reinforcement strategies on the fracture strength of endodontically treated anterior teeth with overflared canals

BACKGROUND: This study is done to evaluate the effect of different reinforcement techniques of overflared root canals with fiber posts on the fracture resistance of endodontically treated anterior teeth. It also introduces a new technique for simultaneous reinforcement and cementation of fiber posts using dual-cured core build-up composite resin. MATERIAL AND METHODS: The crowns of 48 single-rooted maxillary anterior teeth were cut and randomly divided into 4 groups (n=12) based on root reinforcement techniques after root canal treatment and post space preparation: Group 1: self-adhesive resin cement (SARC), Group2: dual-cure composite resin (DCC), Group3: Composite resin reinforcement (CRR), Group 4: Direct anatomical post (DAP). Then a core was made for the roots. The periodontal ligament was simulated using a thin layer of PVC impression material. A universal testing machine applied a compressive force to the lingual surface at an angle of 135 ° and 1 mm/min speed. Data were analyzed using One-Way ANOVA and a post-hoc Tukey test. Fracture patterns were analyzed using the Chi-square test (p<0.05). RESULTS: The difference between the control and DAP group was statistically significant (p=0.01), but there were no significant differences between other groups (p>0.05). Regarding fracture patterns, there were no significant differences between groups. CONCLUSIONS: All reinforcement techniques increased the fracture strength compared to the control group. However, DAP was the only group that had a statistically significant difference. CRR and DCC presented intermediate values without significant differences. Key words:Fiber post, endodontically treated teeth, root canals, reinforcement, fracture strength.