Aim: This original research was carried out to assess the susceptibility to fracture of root canal treated teeth with composite postendodontic restorations.Materials and methods: Seventy-two sound human mandibular premolar teeth, extracted for various reasons, were selected. For experimental purposes, they were then divided into six groups (n = 12). Groups I and II were designated the negative control (no preparation done) and positive control (cavity preparation was done but left unrestored) respectively. In all other teeth, mesio-occluso-distal (MOD) cavities were prepared, and they were then root canal treated. The other groups were also restored with the respective resins: group III: condensable bulk-fill composite, group IV: bulk-fill flowable resin composite, group V: fiber-reinforced composite, and group VI: conventional resin-based composite. Manufacturerrecommended adhesive systems for respective restorative resins were used.To avoid desiccation of the specimens, they were kept in distilled water for 24 hours at body temperature. The specimens were then subjected to compressive loads until they fractured. Statistical analysis was performed using analysis of variance (ANOVA) and post hoc Tukey tests.Results: Statistically significant results were observed among all groups. The highest and lowest values were noted with groups I and II respectively (p = 0.05).
Conclusion:The resistance to fracture in root canal-treated teeth with everX Posterior, fiber-reinforced bulk-fill composite was the highest.