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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 x 10 mm x 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. [ABSTRACT FROM AUTHOR]

Marked bactericidal activity of the electrolyzed acid water (EAW) and its less undesirable effects on biological tissues and the environment has been successfully utilized in dental practice. A review of literature reveals that not many studies have been performed to determine the disinfection effect of EAW on heat cured acrylic denture bases. The objective of the study is to determine the efficacy of EAW in disinfecting heat cured acrylic resin specimens as compared to the efficacy of disinfecting the specimens using 2% glutaraldehyde. Heat cured acrylic resin plates were immersed in Bacteria suspensions of Staphylococcus aureus and later disinfected using EAW which was produced using a custom made electrolyzing apparatus and 2% glutaraldehyde for different time intervals. The numbers of surviving bacteria were counted. As the control, the bacteria attached on the specimens were counted with out any disinfection treatment. The results obtained were statistically analyzed using ANOVA and post-hoc test. The disinfection potential of 2% glutaraldehyde was better than EAW when the specimens were disinfected for 1 and 3 min. Where as when the disinfection time was increased to 5 min there was no difference between EAW and 2% glutaraldehyde. However considering that the disinfecting time can be easily extended to 5 min, EAW can be effectively used for disinfecting the acrylic denture. [ABSTRACT FROM AUTHOR]