Abstract

Objective: To evaluate the fracture resistance of endodontically treated teeth restored with different high-viscosity bulk-fill resin composites. Material and Methods: Forty extracted human upper premolars were endodontically treated and divided into four groups based on the bulk-fill resin composite used: CO: Scothbond Multi-Purpose + Filtek Z350XT; SF: Scothbond Universal + Filtek Bulk Fill; SO: OptiBond All-in-one + SonicFill; and, TT: Tetric N-Bond Universal + Tetric N-Ceram Bulk Fill. Universal adhesive systems were applied using the self-etching technique. After 24 hours, specimens underwent compressive loading at 1mm/min, and fracture patterns were evaluated. Data were statistically analyzed using one-way ANOVA and Tukey's post-test (p>0.05), while fracture patterns were assessed with the chi-square test (p<0.05). Results: Fracture resistance was similar across groups (p>0.05), with favorable fractures observed in the CO and SF groups. Conclusion: The fracture resistance of endodontically treated teeth restored with bulk-fill resin composites does not differ from those restored with conventional nanohybrid resin composites.