Fracture Resistance of Endodontically Treated Premolars Restored with New Short Fiber-reinforced Composite

This study aimed to evaluate the fracture resistance of endodontically treated teeth restored with a new short fiber-reinforced composite (SFRC) restorations and to compare it with flowable bulk-fill composite when applied in the same manner. A total of forty-eight extracted first maxillary premolars were collected and randomly assigned to into four groups (n=12). Root canal treatments and mesio-occlusal-distal (MOD) coronal preparations were performed on three of the groups, while group 1 consisted of intact teeth. Two groups were restored with the study material: group 3 restored with Ever X Flow composite, and group 4 restored with tetric n-flow bulk fill. Group 2 was left without canal obturation or coronal restoration. The composites were applied in a 4 mm layer, followed by a conventional composite layer of 2 mm thickness to replace an enamel. A compression load test was undertaken for all groups, and the data were analyzed using one-way ANOVA and Bonferroni tests. The results showed that the Ever X Flow group had the highest mean compression load, which, was significantly different from group 2, but not significantly different from the other two groups (p > 0.05). The findings suggest that using flowable SFRC as a restorative material, without the application of fiber posts or other cores, may achieve favorable results and enhance the fracture resistance of treated teeth.