Journal of Research and Advancement in Dentistry
Official publication of Magadh University and Kolhan University, Government of Bihar and Jharkhand, India
Official publication of Magadh University and Kolhan University, Government of Bihar and Jharkhand, India
Year : 2021
Volume : Volume 12
Issue : Issue 2
Address for correspondence :
Dr. Nirupama Naidu Vemali
nirupama.dr@gmail.com
Background: Flexural strength of provisional restorative materials is of particular concern with long span fixed partial dentures or in areas of heavy occlusal forces. The purpose of this study is to compare and evaluate the flexural strength of four commercially available conditioned provisional restorative materials before and after thermal cycling. Materials and Methods: Eighty identical samples of dimensions 25×2×2 mm were fabricated from four materials (Heat Cure Acrylic (DPI), Tempron (GC), Protemp 4 (3M ESPE), Revotek LC (GC) ) according to ADA/ANSI specification #27(n=20 for each material). All these samples were stored in artificial saliva for 14 days in an incubator at 37°C. Ten samples from each material (n=40) were subjected to thermal cycling for 2500 cycles (5° to 55°C) and the remaining forty samples were a used as the control group. All specimens were subjected to a standard 3-point bending test with a universal testing machine at a crosshead speed of 0.5mm/min. Results: The lowest and highest mean flexural strengths before and after thermal cycling, were found for Revotek LC, a light cure composite resin and Protemp 4, a self-cure composite resin respectively. Thermal cycling has significantly decreased the mean flexural strength values of all the materials except for Tempron, which is a poly ethyl methacrylate resin. Conclusions: Bis acryl provisional materials exhibited greater flexural strength values than the methacrylate and UDMA resin materials compared in this study. Thermal cycling of the specimens significantly decreased the flexural strength of all the materials except Tempron. These greater values should be considered while fabricating provisional restorations, especially when long-term use or long span fixed partial dentures are planned.
Keywords: Fixed Partial Denture, Provisional Restorations, Thermal Cycling, Heat Cure Acrylic, Self-Cure Composite, Poly Ethyl Methacrylate, Light Cure Composite.
