Fracture Resistance of Dental Restorative Fiber-reinforced Composites- A Systematic Review

Large cavity designs and access cavities impair endodontically treated tooth fracture resistance. As the tooth's strength is known to reduce significantly after the root canal treatment, occlusal loading as a result of functions such as chewing, biting and certain parafunctional tendencies makes the endodontically treated tooth vulnerable to fracture. Hence, after endodontic treatment, it is vital to give adequate and appropriate restorative material to avoid tooth fractures. Accordingly, the choice for such restorative material should be dictated with the property of fracture resistance. The goal of this study was to conduct a systematic review and critical analysis of available data from in vitro studies examining the fracture resistance of endodontically treated teeth repaired with fiber-reinforced composites. A comprehensive literature search was performed using PubMed Central, Medline, Scopus, ScienceDirect, Google Scholar and LILACS. A manual search of the reference lists of the articles was also performed. Two reviewers scrutinized the papers for eligibility based on inclusion/exclusion criteria and extracted data. The studies were assessed for their potential risk of bias. A total of 15 studies met the inclusion criteria and were subsequently analyzed. Based on modified JBI & CRIS (checklist for reporting in vitro studies) guidelines, along with the methodology and treatment objective, we have formulated 13 parameters specifically to study the fracture resistance. The majority of the research had a moderate or high risk of bias. When compared to traditional hybrid composites, fiber-reinforced composites showed increased fracture resistance of endodontically treated teeth in the majority of investigations. On the other hand, limited evidence was found for the bulk fill composites. Moreover, moderate evidence was found for the fracture resistance of inlays and fiber posts with fiber-reinforced composites for core build up in endodontically treated teeth. No evidence could be found comparing the fracture resistance of crowns/endocrowns and fiber-reinforced composites in endodontically treated teeth. According to the research, using fiber-reinforced composites instead of conventional hybrid composites improves the fracture resistance of endodontically treated teeth. However, there was a high risk of bias in the research considered. No judgments could be reached about the superiority of one material over another based on comparisons between other core restorations.