Avaliação da alteração da microdureza Vickers de resina termoplástica comparada á resina acrílica termopolimerizável após a imersão em bebidas coradas

Abstract

Resin-based thermoplastics have emerged as an option for the frameworks of removable partial dentures due to their excellent aesthetic properties and their non-allergenic nature, as they lack residual monomers and do not contain chromium-cobalt compounds. However, there is limited research on this material that substantiates its long-term use and success. This study aims to compare the variation in Vickers microhardness of thermopolymerizable acrylic resin and thermoplastic acrylic resin before and after immersion in instant coffee and yerba mate, simulating the consumption of these beverages over time. For the research, 60 test specimens were fabricated, with 30 made of thermoplastic resin divided into 3 groups of 10 each and 30 made of thermopolymerizable acrylic resin divided into 3 groups of 10 each. The test specimens were randomly distributed, where 10 test specimens of each resin were immersed in instant coffee, 10 in yerba mate (tereré), and 10 in water as the control group. The immersion took place over a period of 24 consecutive days, with daily changes, simulating 2 years of beverage consumption. Measurements were taken immediately after the polishing of the resins (t0) and after immersion (t1). After averaging the data points, the data underwent two-way ANOVA and Tukey tests. The results obtained demonstrate a statistically significant difference between the two resins before immersion. After immersion, the thermoplastic resin (flexible) exhibited lower microhardness compared to the thermopolymerizable acrylic resin, regardless of the immersion beverages. Among the beverages, yerba mate (tereré) showed the lowest microhardness value. The control group (water) had a higher microhardness value, regardless of the type of resin.