Comparison of compressive strength, tensile strength, flexure strength and impact strength of reinforced acrylic resin with TiO2 nanoparticles and conventional acrylic resin

Abstract

Objective: Polymethyl methacrylate (PMMA) is one of the usual and general materials in prosthetic dentistry. Because of its excellent appearance, ease in processing, and repairability, make PMMA as an excellent denture base material so PMMA has proved to be the most satisfactory denture base material currently available. This material most commonly used for the fabrication of complete dentures. One of the limitations of acrylic resin is their poor mechanical properties such as low tensile strength and fracture resistance under body conditions. The current study was performed to enhance the mechanical properties including tensile, impact, flexural and compressive strength of heat-cure acrylic resin reinforced by TiO2 nano powder added into the resin matrix. Methods: This study is an in vitro experimental research. The test samples were prepared to compare their strength of samples with a control level. For evaluation of four mechanical properties (tensile, impact, flexural and compressive strength) 9 samples for each concentration (0.5, 1 AND 2%) and finally 144 samples have been prepared. TiO2 NPs were mixed by PMMA in amalgamator device with three groups by 0.5, 1 and 2 %wt. of TiO2. Mixing of TiO2 nanoparticles were manually blended with PMMA and then the mixture was blended. Before curing, the resulting paste was packed into steel molds using an oscillator to remove pores. After curing, the specimens were removed from the molds for inserting on test machine. One-way analysis of variance (ANOVA) followed by multiple comparison test (ScheffeEs test) used for compare of the obtained results for each test group. Statistical significance was set at P<0.01. Results: The TiO2 with 1%wt has best mechanical properties especially on impact and flexural strength with compared by other samples. The sample with 2% TiO2 has low mechanical properties especially in flexural strength. In the sample with 0.5% TiO2 there is no significant difference according to ANOVA results. Conclusion: PMMA with 1% Tio2 has signicant increases in mechanical properties. Extra content of TiO2 in PMMA matrix decrease the mechanical properties