Evaluation of effect of aramid and carbon fiber reinforcement in autopolymerizing repair resin used to repair heat polymerized polymethyl methacrylate resin – an in vitro study

Background: Denture fractures are common, reflecting the fact that both impact strength and flexural strength of the material are barely adequate. Objective: The purpose of the study was to evaluate the effect of aramid and carbon fiber reinforcement in autopolymerizing resin used to repair heat polymerized polymethyl methacrylate at 1mm and 3mm thickness respectively. Materials and methods: A total of 180, resin specimens using conventional heat polymerized PMMA resin and measuring (64mm×10mm×3.3mm) were fabricated in a preformed machined mold. A cantilever type bending forces was applied to each specimen till it fractured. The resin was relieved from bonding area to create 1mm and 3mm space. These fragments were realigned and repaired using conventional autopolymerizing resin and reinforced with carbon or aramid fibers. The specimens after repair were tested for impact strength using Izod type impact tester and for flexural strength using Universal testing machine. The data obtained was subjected to statistical analysis. Results: The results demonstrated that the mean impact strength values was significantly higher in polyaramid fiber reinforced PMMA repair group at 3mm thickness and the mean flexural strength values was significantly higher in polyaramid fiber reinforced PMMA repair group at 1mm thickness. Conclusion: Within the limitation of this study, it can be concluded that fiber reinforcement improved the strength of repair of the fractured heat-polymerized denture base. The strength after repair may be influenced by the gap at the repair region.