Assessment of fracture resistance in endodontically treated premolars restored using various bulk-fill composites

Endodontically treated premolars are structurally compromised and highly susceptible to fracture, necessitating restorative materials that can effectively reinforce tooth strength. Therefore, it is of interest to evaluate and compare the fracture resistance of endodontically treated maxillary premolars restored with three bulk-fill composites and a conventional incremental composite. Eighty premolars were endodontically treated, prepared with standardized MOD cavities and allocated into four groups (n=20): Filtek One Bulk Fill, Tetric EvoCeram Bulk Fill, SonicFill 3 and Filtek Z250. Fracture resistance was tested using a universal testing machine and analyzed with one-way ANOVA and chi-square tests. SonicFill 3 demonstrated the highest fracture resistance, followed by other bulk-fill composites, while the conventional composite showed the lowest values, indicating superior reinforcing potential of bulk-fill materials.