Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine.

Denture bases may undergo color change over time induced by pigment accumulation within their body; however there is a lack of information regarding the role of yerba mate tea in this process. This work evaluated the effect of five common beverages, including yerba mate tea, on color changes of acrylic denture base resins processed in three different ways. Three different processing techniques were used (P1--microwave irradiation/microwave activated resin; P2--heat polymerization/conventional heat activated resin and P3--microwave irradiation/conventional heat polymerized resin) to make twenty five resin discs each (3.0 mm thick x 20 mm diameter), totaling seventy-five resin discs. The discs made with each technique were randomly divided into five groups (n = 5) and placed in the following solutions: G1-water; G2-cola; G3-coffee; G4-yerba mate tea; G5-red wine, for 30 days at 37 degrees C. The solutions were renewed every 3 days. Color change on the CIE-L*a*b* scale was measured with a Konica-Minolta CR-10 colorimeter and compared with original L* a* and b* values of each specimen prior to immersion. Data were analyzed using 2-way ANOVA, and showed no difference among techniques and significant statistical differences among solutions (p < 0.05). Tukey's post-hoc test showed that the lowest color changes were for water and cola, which were undistinguishable from each other; coffee produced the second lowest color change; yerba mate tea produced second greatest color change, while the greatest color change was produced by red wine. Within the limitations of this study, it was concluded that almost all the solutions used can change color in acrylic resin, especially yerba mate tea, considered distinguishable by professionals, and red wine, considered distinguishable by patients and clinically unacceptable.

As bases protéticas em resina acrílica podem sofrer alteração de cor com o tempo em função do acúmulo de pigmentos em seu interior, porém há carência de informação sobre o efeito do consumo de chimarrão neste processo. Este trabalho avaliou o efeito de cinco bebidas diferentes, incluindo chimarrão, na cor de resinas acrílicas processadas por três técnicas diferentes. Vinte e cinco discos de resina acrílica (3 mm de espessura x 20 mm de diâmetro) foram fabricados a partir de cada uma das técnicas de processamento (P1 ­ polimerização por microondas / resina termopolimerizável por microondas; P2 ­ termopolimerização convencional / resina termopolimerizável convencional e P3 ­ polimerização por microon - das / resina termopolimerizável convencional). Os discos foram aleatoriamente divididos em cinco (n=5) grupos por técnica: G1 ­ água; G2 ­ refrigerante à base de cola; G3 ­ café; G4 ­ chimarrão e G5 ­ vinho tinto, e foram mantidos imersos em cada uma das respectivas soluções por 30 dias a 37 ºC, com trocas das soluções a cada 3 dias. A cor final foi medida na escala CIE-L*a*b* com um colorímetro Konica-Minolta CR-10 e comparada com os valores originais de L*a*b* prévios à imersão de cada corpo-de-prova. Análise de Variância para dois fatores não encontrou diferenças entre as técnicas e apontou diferença estatisticamente significativa (p<0,05) entre as soluções. Teste complementar de Tukey mostrou que as menores variações de cor ocorreram para água e refrigerante à base de cola; o café apresentou a segunda menor variação de cor; o chimarrão apresentou a segunda maior variação enquanto a maior variação de cor foi encontrada para o vinho tinto. Conclusões: Concluiu-se que quase toda solução utilizada provoca mudança de cor nas resinas acrílicas, principalmente com chimarrão e vinho, consideradas distinguíveis por profissionais e clinicamente inaceitáveis respectivamente.

Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine. / Color change in acrylic resin processed in three ways after immersion in water, cola, coffee, mate and wine.

Denture bases may undergo color change over time induced by pigment accumulation within their body; however there is a lack of information regarding the role of yerba mate tea in this process. This work evaluated the effect of five common beverages, including yerba mate tea, on color changes of acrylic denture base resins processed in three different ways. Three different processing techniques were used (P1--microwave irradiation/microwave activated resin; P2--heat polymerization/conventional heat activated resin and P3--microwave irradiation/conventional heat polymerized resin) to make twenty five resin discs each (3.0 mm thick x 20 mm diameter), totaling seventy-five resin discs. The discs made with each technique were randomly divided into five groups (n = 5) and placed in the following solutions: G1-water; G2-cola; G3-coffee; G4-yerba mate tea; G5-red wine, for 30 days at 37 degrees C. The solutions were renewed every 3 days. Color change on the CIE-L*a*b* scale was measured with a Konica-Minolta CR-10 colorimeter and compared with original L* a* and b* values of each specimen prior to immersion. Data were analyzed using 2-way ANOVA, and showed no difference among techniques and significant statistical differences among solutions (p < 0.05). Tukeys post-hoc test showed that the lowest color changes were for water and cola, which were undistinguishable from each other; coffee produced the second lowest color change; yerba mate tea produced second greatest color change, while the greatest color change was produced by red wine. Within the limitations of this study, it was concluded that almost all the solutions used can change color in acrylic resin, especially yerba mate tea, considered distinguishable by professionals, and red wine, considered distinguishable by patients and clinically unacceptable.