Comparative evaluation of flexural strength of 8 heat cured PMMA denture base resin reinforced with different concentrations of silanized TiO 2 nanoparticles – An in vitro study

Introduction: Polymethyl methacrylate (PMMA) is the most frequently used material in denture fabrication. Down side of PMMA dentures is it breaks within a few years after fabrication[4]such dentures flex in the mouth during chewing and due to repeated small loadings during mastication lead to the midline fracture due to poor flexural strength of denture base resin. The purpose of this study was to find out the effect on flexural strength of heat cured PMMA denture base material after incorporation of 1%, 3%, and 5% by weight of silanized titanium dioxide (TiO2) nanoparticles. Materials and Methods: For test samples preparation, TiO2 nanoparticles were coated with a trimethoxysilylpropylmethacrylate (TMSPM) before sonicated in monomer with the percentages 1%, 3%, and 5% by weight; after sonication it was mixed with PMMA powder using conventional denture fabrication procedure. Then total 60 samples for study was prepared; 15 samples for each four groups, i.e. that is one control group and three experimental groups. First control group was prepared from PMMA without incorporation of TiO2 nanoparticles, the second group with the incorporation of 1 wt% TiO2 nanoparticles, the third group with 3 wt% TiO2 nanoparticles, and the fourth group with 5 wt% TiO2 nanoparticles. Flexural strength test was then conducted on each sample. Results: Each group was evaluated for Flexural strength test, and it was found that increasing the wt% of nanoparticles, there was a significant increase in flexural strength of PMMA denture base resin. P value suggested that the difference of mean percent increase across all groups was statistically significant with p < 0.05. Conclusion: It was observed that flexural strength of denture base resin incorporated with 5 wt% TiO2 nanoparticles was having highest flexural strength among all.