Effect of titanium oxide nanoparticles on polymerization reaction of heat and microwave cured polymethylmethacrylate: in vitro study

Abstract

Abstract Background Titanium Oxide Nanoparticles (TiO2NPs) have been introduced to polymethyl methacrylate (PMMA) denture base to enhance its mechanical, physical, and biological performance. Objectives This research aimed to assess the effect of adding TiO2NPs on the degree of polymerization and morphological characterization of heat and microwave cured PMMA. Materials and methods Fabrication of PMMA specimens which were categorized according to the curing technique into heat cured (group I) and microwave cured (group II). Each group was subdivided into two subgroups A and B according to the addition of TiO2NPs. A total number of 24 specimens were fabricated. Each subgroup contains 6 specimens. The specimens were characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDX). The polymerization reaction of specimens was assessed by Attenuated Total Reflection Fourier-Transform Infra-Red Spectroscopy (ATR-FTIR). Results were statistically analyzed using an independent T-test and one-way ANOVA. The significance level was set at p < 0.05. Results SEM/EDX revealed that TiO2 NPs appeared as bright areas in the matrix of both groups. The matrix showed organic impurities and minute internal cracks, but group IIB (microwave-cured PMMA with TiO2NPs) showed higher organic impurities than heat-cured PMMA. The FTIR revealed that the addition of 3% by weight TiO2NPs decreased the degree of polymerization of both heat and microwave-cured PMMA but the decrease was insignificant (p > 0.05). Conclusions Incorporation of 3% by weight TiO2NPs does not significantly affect the degree of polymerization of both heat and microwave-cured PMMA. Hence, denture materials can benefit from the advantages of the TiO2NPs without any alterations to their structures. Graphical abstract