Evaluating the fracture resistance of fiber reinforced composite restorations - An in vitro analysis

Abstract
Background: Laboratory reports show that fiber-reinforced composites have improved fracture resistance over traditional composites. However, limitations in the biomechanics of tests to evaluate the fracture resistance of fiber-reinforced composites need to be considered for accurate clinical applications. Aim: To assess the fracture resistance of particulate filler composites, glass fiber-reinforced composites, and polyethylene-fiber reinforced composites by analyzing the different fracture types and failure patterns. Materials and Methods: A standardized incisal (Group I) and mesioincisal fractures (Group II) were prepared on human maxillary central incisors. The test samples were further subdivided according to the restorative material used; particulate filler composites (Filtek Z 250), glass fiber-reinforced composites (fibre splint), and polyethylene-reinforced composites (Ribbond). The type of fractures was evaluated under the stereomicroscope and the failure patterns were analyzed using the graphical output from Universal Testing Machine. Statistical Analysis: The Chi-square test of association was used to test the association between fiber-reinforced composites and fracture resistance of tooth restoration complex. Results: No statistical association was observed between fiber-reinforced composites to the type of fractures in both incisal (P = 0.29) and mesioincisal restoration (P = 0.27). A significant association was observed between the fiber-reinforced composites to the failure patterns in both the incisal (P = 0.005) and mesioincisal restoration (P = 0.007). Conclusion: The glass and polyethylene fiber-reinforced composites showed improved fracture resistance properties than the traditional particulate filler composites in both incisal and mesioincisal restorations.