Abstract
The biomechanical function of teeth with endodontic treatment is directly impacted by the restorative material chosen. It has been demonstrated that biomimetic restorative techniques, such as fiber-reinforced composites, polyethylene fibre reinforcement, and bioactive core materials, more successfully mimic the functional characteristics of natural dentin and enamel than traditional composites. Therefore, it is of interest to evaluate the strengthening effect of biomimetic restorative materials on root canal-treated teeth subjected to orthodontic intrusion and extrusion. Forty extracted maxillary premolars were restored using short fibre-reinforced composite, polyethylene fibre with composite, biodentine, or conventional composite, and tested under 150 g orthodontic force. Teeth restored with fibre-based materials exhibited significantly higher fracture resistance than biodentine and control groups (p < 0.05). Favorable fracture patterns predominated in fibre-reinforced groups, while conventional composites showed mainly unfavorable fractures. Biomimetic restorations, particularly fibre-based materials, enhance fracture resistance and promote favorable failure modes during orthodontic loading.