An In Vitro Evaluation of Flexural Strength of Two Provisional Restorative Materials Light Polymerised Resin And Autopolymerised Resin.

Abstract

Statement of problem: Flexural strength is important in determining the strength of interim restorations and it is especially important in long span and long term interim restorations. Studies comparing the flexural strength of provisional restorative materials are limited and inconclusive. Aim: To compare the flexural strength of provisional restorative material fabricated using light polymerized composite resin, Urethane dimethacrylate (UDMA) and auto polymerized resin, Poly Methyl Methacrylate (PMMA) Materials And Methods: This study included 40 specimens. Twenty bar-shaped specimens were fabricated for each group Polymethyl Methacrylate (PMMA), and Urethane dimethacrylate (UDMA) with the use of a split machined metal mold. These specimens were stored in artificial saliva for 10 days. Flexural strength was calculated using three point bending test under universal testing machine. Data were analysed using student-ttest (α=0.05) @ 90% power. Results: The mean flexural strength of provisional restorative specimen fabricated using Poly Methyl Methacrylate (PMMA-134.1 Mpa) was significantly higher than Flexural strength of provisional restorative specimen fabricated using urethane dimethacrylate (UDMA-107.8 Mpa). Conclusion: Within the limitations of this study by analyzing the results, it was concluded that the flexural strength of polymethyl methacrylate (PMMA) is comparatively better than the flexural strength of Urethane dimethacrylate (UDMA). PMMA could be a better provisional restorative material for an extended period, when the patient exhibits parafunctional habits, or when long-span prosthesis is planned.