Evaluation of Immediate and Delayed Flexural Strength of Poly Methyl Meth Acrylate and Bis Acryl Composite Based Provisional Restorative Material - An in Vitro Study

INTRODUCTION: The demand for tooth coloured restorations has increased significantly in recent years due to improved techniques, materials and also patient’s demand for aesthetic restorations. Accurate temporary restorations are essential and serve various functions, including protection of the pulpal tissues, preventing bacterial contamination and preservation of the periodontal tissues. Polymethyl methacrylate (PMMA) resins and composite-based resins (CBR) are the most common materials used to fabricate temporary restorations. AIM: The aim of this study was to evaluate and compare the immediate and delayed flexural strength of PMMA (ICERAC- CAD/CAM) and traditional Bis-acryl composite based (ACRYTEMP) provisional restorative material before and after storing in artificial saliva for 7 days followed by thermo cycling and cementation. MATERIALS AND METHODS: Three unit bridges were fabricated with PMMA using CAD CAM technique and Bis-acryl based composite based (ACRYTEMP) by direct technique on the prepared teeth. Both the groups were subjected to thermocycling for 1500 cycles between 50 C and 55 0C with a dwell time of 30 sec followed by cementation with the provisional cement. After the thermocycling and cementation of each sample on to the master model, flexural strength was evaluated immediately and after storing in artificial saliva for 7 days using the universal testing machine. RESULTS: Results revealed that the three unit bridge after storing in artificial saliva PMMA using CAD CAM technique shows better strength than that of Bis-acryl based composite based (ACRYTEMP) material. CONCLUSION: It was concluded that the provisional restoration fabricated using CAD/CAM (polymethyl methacrylate) interim restorations has better flexural strength than traditional Bis–acryl composite (ACRYTEMP) interim restorations in the oral environment.