AVALIAÇÃO DA INFLUÊNCIA DE SUBST NCIAS CORANTES NA ESTABILIDADE ÓPTICA DE POLÍMERO TERMOPLÁSTICO EM COMPARAÇÃO A RESINA ACRÍLICA TERMOPOLIMERIZÁVEL: ESTUDO IN VITRO

Abstract

Flexible polymers for dental prostheses have the ability to offer a visually appealing alternative to traditional prostheses, which feature metal in aesthetic regions and in the smile line. They are often used in removable partial dentures. The aim of this study was to evaluate the degree of staining between common thermosetting acrylic resin and flexible thermoplastic polymers (Deflex® Classic SR) when exposed to cola soft drinks, yerba mate (Ilex paraguariensis) and instant coffee. In the study, 80 specimens were made, n=40 from a circular matrix of thermally activated acrylic resin and n=40 from a flexible thermoplastic polymer manufactured in CAD/CAM. After finishing and polishing, the specimens were randomly divided into 4 groups (n=10) in each material, where they spent 24 days (simulating daily use for 2 years, with each day representing 1 month) immersed in the staining substances, plus a control group in distilled water. The results were analyzed in 2 stages using a spectrophotometer, initially after finishing and polishing (T0), and after 24 days of immersion with a daily change of substances (T1). Statistically significant differences in color change (ÄE) were found between all groups (p < 0.005) after 24 days of immersion. Considerable changes were observed when the samples were immersed in coffee and cola. A major color change was observed when the specimens were immersed in yerba mate.