Comparative study of the effect of incorporating SiO2 nano-particles on properties of poly methyl methacrylate denture bases

Abstract

The aim of this investigation was to assessand comparethe impact of incorporation of nanosilica sand (crystalline) and nano-silica (amorphous) on the properties (impact strength, transverse strength, and hardness)of heat-cure type acrylic resin denture base material, polymethylmethacrylate (PMMA). Nanoparticles(NPs) with different concentrations (3%, 5% and 7%) were incorporated by weight into PMMA and processed under optimal conditions.161 samples were prepared for this study.These samples were placed in three groups according to the tests performedandeach group consisted of seven sub-groups according to the percentage of NPs added. Charpy test for impact strength, transverse strength test and hardness test (shore D) were conducted. The morphology, size distribution and crystallinity of the NPs were estimated by scanning electron microscope, atomic force microscope, and X-Ray diffraction respectively.The results show that each investigated property was enhanced after NPs filler wasincorporatedwhen compared to control group. Highly significant improvements in impact strength,transverse strength and hardness were observed with addition of NPsto PMMA at 3%, 5% and 7% by weight. However, compromised mechanical properties is still a drawback of PMMA , hence it can be easily damaged by accidents or high mastication forcesduring denture wear. One of the ways of improving the mechanical properties of PMMA based materials may be NPsincorporation which canimprove the physical and mechanical properties. Optimum nanoparticle doses can yield superior mechanical properties.