The effect of different solutions and thermocycling on the Vickers hardness of acrylic resin denture teeth

Abstract

Aim: The aim of this study was to evaluate the effect of artificial saliva, disinfectant solution, distilled water, and thermocycling on Vickers hardness of 4 commercial brands of acrylic resin denture teeth. Methodology: Four different brands of acrylic resin denture teeth (Major Dent, Acry Lux, Acry Rock, Imident Lux) were evaluated. 15 anterior and 15 posterior teeth of each group embedded in autopolymerized acrylic resin. The occlusal surfaces of posterior teeth and the vestibule surfaces of anterior teeth were flattened by using silicon carbide paper. After polishing, microhardness measurements were repeated three times for each teeth. The teeth were submitted to different conditions: (1) storage in distilled water at 37±2°C for 7 days; (2) storage in artificial saliva at 37±2°C for 30 days and (3) storage in 1 % sodium hypochlorite. After, thermal cycling between 5 and 55 °C for 2500 cycles was made. The microhardness measurements were repeated. Data were analyzed with one-way analysis of variance (ANOVA) and Duncan test (p<0.05). Results: There were statistically significant differences between initial and final microhardness values of different brands of acrylic resin denture teeth. Anterior teeth showed lower microhardness values than posterior teeth. Conclusions: Storage in different solutions and thermal cycling significantly reduced the Vickers hardness of the acrylic resin denture teeth.