Fracture resistance of teeth restored with polyethylene fibers reinforced composite restorations: a systematic review and meta-analysis of in vitro studies

Aim This systematic review and meta-analysis aimed to evaluate the fracture resistance of permanent teeth restored with polyethylene fiber-reinforced composite resin restoration. Material and methods The following PICOS framework used was: Population, permanent teeth requiring restorative treatment; Intervention, polyethylene fiber use; Control, composite resin restorations without fiber reinforcement, or conventional fiber posts; Outcome, fracture resistance (in Newtons); Study design, in vitro studies. A literature search was conducted independently by two reviewers up to May 18, 2025, using electronic databases (PubMed, ISI Web of Science, SciELO, Scopus, and Embase). In vitro studies examining the fracture resistance of permanent teeth restored with polyethylene fiber-reinforced resin composite restorations were included. Meta analyses were performed by comparing the standardized mean differences in the fracture resistance of teeth restored using polyethylene fibers and the teeth restored only with resin composite. Additional analysis was performed comparing the risk difference of the number of unfavorable fractures. Separate analyses were performed when fiber posts were used. A p -value of less than 0.05 was considered statistically significant. Results The fracture resistance of polyethylene fiber-reinforced restorations was higher compared to non-fiber reinforced composite restorations ( p < 0.001). Also, the number of unfavorable fractures were significant lower when polyethylene fibers were used ( p < 0.001). Conclusion The findings suggest that the fracture resistance of permanent teeth may be improved with the use of polyethylene fibers. However, clinical performance outcomes are necessary to validate these in vitro results. Systematic Review Registration The protocol for the systematic review was developed a priori and can be accessed at: https://doi.org/10.17605/OSF.IO/5K8XB .