Comparison of titanium dioxide nanoparticles and silver nanoparticles for flexural strength once incorporated in heat-cure acrylic denture base resin: An in vitro Study.

Aim: Polymethylmethacrylate (PMMA) resin is the most by and large used denture base material. Denture fractures are sequential to the flexure or impacting forces. Different nanoparticles such as titanium dioxide and silver nanoparticles have been used to improve its antimicrobial properties. There are limited data on their effect on flexural strength. The aim of the study was to assess the effect of silver nanoparticles and titanium dioxide nanoparticles addition on flexural strength of PMMA resins.

Settings and design: One hundred and thirty specimens divided into four groups: Control Group A, TiO₂-reinforced Group B, silver nanoparticles reinforced Group C, and mixture of TiO₂ and silver nanoparticle reinforced Group D. Each reinforced group further divided based on concentrations -0.5%, 1%, 2%, and 3%.

Materials and methods: Rectangular metal models of the American Dental Association (ADA)- specified dimensions: 65 mm × 10 mm × 3 mm were used to form a mold space for the fabrication of specimens. Three-point bend test was used to determine the flexural strength of the samples after immersion in distilled water for 2 weeks.

Statistical analysis: The data collected were subjected to analysis of variance followed by post hoc Tukey's test.

Results: The comparison of the mean flexural strengths showed a statistically significant gradual decrease on increasing the concentrations of nanoparticles. Maximal flexural strength was seen in the control group and least with 3% Ag + TiO₂ Nps. The modified specimen also showed color changes.

Conclusions: In an in vitro environment, addition of TiO₂ and silver decreases the flexural strength of the PMMA. It also causes visible color changes.