Abstract
OBJECTIVE: To assess the biomechanical performance of the application of polyethylene fiber and fiber-reinforced composite resins in direct restorations. MATERIALS AND METHODS: An electronic search was performed in Cochrane Library, Embase, and Pubmed on January 16th, 2025, with previously identified MeSH and free text terms by two independent authors. A total of 1127 papers were initially obtained. Exclusion criteria comprised nonrelevant materials, evaluation of pins and posts, material characterization, indirect or provisional restorations, and the use of artificial, animal, or immature teeth. RESULTS: From the 754 studies remaining after duplicates removal, 679 were excluded after title and abstract screening, followed by the exclusion of 7 papers after full-text assessment for eligibility. Additionally, 10 full texts were not obtained after requesting the authors. Therefore, a total of 58 studies were included in this scoping review. When compared to conventional composites, fiber-reinforced composite resins proved to be beneficial in 82.1% of the articles, while polyethylene fibers improved the biomechanical performance in 91.7%. CONCLUSIONS: The individual application of fiber-reinforced composite resins and polyethylene fibers demonstrates promising potential in dental direct restorations. No adverse biomechanical outcomes were reported, with findings either supporting their use or indicating no significant difference. Nevertheless, the results are ambiguous and insufficient to directly compare both materials or assess the effects of their combined use. It is recommended to establish standardized guidelines for future research to enhance the comparability of results, explore long-term outcomes, and customize study designs to more closely resemble clinical settings. CLINICAL SIGNIFICANCE: Fiber-reinforced composite resins and polyethylene fibers have emerged in an attempt to improve the biomechanical performance of direct restorations. However, a comprehensive review of the existing literature is necessary to assess their influence on biomechanical outcomes and identify knowledge gaps, thereby guiding future research.