Fracture Resistance of Endodontically Treated Teeth with Class II Restorations Restored with New Short Fiber-reinforced Composite: An in-vitro study

Abstract This study aimed to evaluate the fracture resistance of endodontically treated teeth restored with new short fiber-reinforced composite (SFRC) restorations and compared it with flowable bulk-fill composite when used in the same way. Forty extracted first maxillary premolars were collected and distributed randomly into four groups (n = 10). Root Canal Treatments and MOD coronal preparations were done in three groups since group 1 had solid teeth. Two groups were restored with one of the study materials, group 3 was restored with Ever X Flow composite, and group 4 was restored with tetric n-flow bulk fill, whereas group 2 was left without canal obturation or coronal restoration. Composites were applied in a 4 mm layer, and a conventional composite layer was applied in a 2 mm thickness as an enamel replacement. Compression load test was done for all groups, and then data were analyzed with one-way ANOVA and Bonferroni tests. Results showed that the Ever X Flow group had the highest mean of the compression load test, significantly different from group 2, and not significantly different from the other two groups (p > 0.05). The use of flowable SFRC as a restorative material without using fiber posts or other cores may achieve a good result and enhance the fracture resistance of treated teeth.