Resistência à fratura de restaurações em resina composta direta reforçadas com fibras de polietileno em fita: uma revisão sistemática e meta-análise

Abstract

Although composite resin is universally indicated as the material of choice for direct restorations, biomechanical failures still occur in extensive cavities. Reinforcement with polyethylene fibers has been proposed to mitigate these failures and enhance the mechanical properties of restorations. The aim of this meta-analysis was to evaluate the fracture resistance of premolars with class II preparations restored with polyethylene fiber–reinforced composite resin. Fracture resistance was compared between two groups: (1) composite resin restorations reinforced with polyethylene fiber tape and (2) nanohybrid and microhybrid composite resin restorations. A literature search was conducted in the Medline (PubMed), Web of Science, Scopus, LILACS, and Google Scholar databases from March 6 to November 28, 2025. Only in vitro studies evaluating fracture resistance of premolars were included in this systematic review. The primary outcome measure for each study was the maximum fracture load, expressed in Newtons (kg × m/s2). This study followed the PRISMA guidelines, with a protocol registered in PROSPERO, and used the QUIN tool to assess risk of bias. Quantitative synthesis was performed using the standardized mean difference (SMD) under a random-effects model (95% confidence interval; p < 0.05). Of the twelve eligible studies, seven were included in the meta-analysis. The results indicated that the use of polyethylene fibers significantly increased fracture resistance (SMD = 1.66; p = 0.002) compared with control groups, despite high heterogeneity (I2 = 87%) attributed to methodological variations. It is concluded that the incorporation of polyethylene fibers into direct class II nanohybrid composite resin restorations, whether conventionally polymerized or bulk-fill, in premolar teeth is an effective strategy to enhance mechanical resistance and optimize stress redistribution within the remaining tooth structure.