An in vitro assessment of physicomechanical properties of heat-cured denture base resin disinfected by ozonized water

Abstract

Aim: This study investigates the influence of ozonized water disinfection on flexural strength, surface roughness, and surface microhardness of heat-cured denture base material [(polymethyl methacrylate (PMMA)]. Materials and methods: A total number of 90 specimens were prepared from heat-cured denture base material. In the control group (n = 30), 10 specimens from each test were immersed only in distilled water at 37°C for 48 hours before testing. For the two experimental groups (n = 60), 10 specimens of each group in each test were immersed in 2% chlorhexidine for 10 minutes and another 10 specimens were immersed in ozonized water with a concentration of 10 mg/L for 30 minutes. In the flexural strength test, specimens were subjected to three-point loading at a crosshead speed of 5 mm/minute of a universal testing machine. Hardness measurements using Vickers microhardness tester and roughness measurements by the Surftest analyzer were performed. Measurements of flexural strength, surface roughness (Ra, μm), and hardness (kg/mm2) were analyzed using one-way analysis of variance (ANOVA) and Tukey least significant difference (LSD) test (α​ = 0.05). Results: Flexural strength values of ozonized water disinfected specimens were insignificantly decreased. However, the use of ozonized water disinfection significantly increased roughness values. At the same time, microhardness values significantly decreased. Conclusion: The use of ozonized water in disinfecting heat-cured denture base resin did not exhibit a deleterious effect on its strength nor surface roughness. Thus, it may be a much more safe disinfection method rather than chlorhexidine chemical disinfectant. Clinical significance: Disinfection of heat-cured PMMA denture base resin using ozonized water may be a more valuable hygienic method compared to chlorhexidine, the most common chemical disinfectant.