Fracture Resistance of over Flared Endodontically Treated Central Incisors Restored with Multiple Prefabricated and Custom-Made Glass Fiber Posts.

Objectives: This study aimed to evaluate the fracture resistance of over flared endodontically treated bovine central incisors restored with prefabricated and custom-made glass fiber posts, using the multi-post approach. Materials and Methods: Sixty-eight crownless over flared endodontically treated incisors were used for this study. The depth of prepared post space was 10 mm, and the remaining dentin thickness of the roots was 1 mm. The samples were randomly divided into four groups (n=17): Group 1: two prefabricated glass fiber posts; group 2: prefabricated glass fiber post + braided glass fiber; group 3: braided glass fiber; group 4: no post. Static load was applied at a crosshead speed of 0.5 mm/min at 135° angle relative to the root longitudinal axis until fracture. The data were analyzed using one-way ANOVA and post hoc Tukey's test at a significance level of P<0.05. Results: Groups 3 and 4 exhibited the maximum (981 N) and minimum (461 N) fracture strength values, respectively. The differences between group 4 and other groups were significant (P<0.001), but the differences between groups 1, 2, and 3 were not significant (P>0.05). Conclusion: Multiple prefabricated and custom-made glass fiber posts significantly increased the fracture resistance of crownless endodontically treated central incisors with over flared root canals.