Evaluation of Color Change of Acrylic and Bisacrylic Resins after Immersion in Different Solutions

Abstract Temporary restorations are of great importance for success in the course and completion of dental rehabilitations. In the face of substances transiting the oral cavity, color stability becomes essential for success during its use, mainly for the maintenance of aesthetics. The objective of the study was to evaluate the influence of the solutions of routine consumption on the color change of two materials used in the preparation of temporary restorations, comparing the stability of the acrylic resin with the bisacrylic resin. For the research, 60 samples were made, 30 of which were made of conventional acrylic resin (DencorLay, Classico Ind. And Com., Sao Paulo, SP, Brazil) and 30 of Protemp 4 bisacrylic resin (3M ESPE, St. Paul, MN) TO 1. The samples were divided into three groups (n = 10) according to the immersion medium: distilled water (control), Cola-Cola® and Coffee. The evaluation of the color change (ΔE) was evaluated according to the difference of the initital and final  color (after 7 days of immersion) through the spectrophotometer (Vita Easyshade Advance 4.0; Vita-zahnfabrik). The results showed that the solutions presented significant staining potential, and that coffee provided the greatest color change for both resins tested (p <0.05). Regardless of the immersion medium, the bisacrylic resin presented the highest values ​​of ΔE. It is concluded that coffee has a high staining potential over the provisional materials and that the bisacrylic resin has a lower color stability compared to the acrylic resin. Keywords: Dental Restoration, Temporary. Acrylic Resins. Polymethyl Methacrylate. Prosthesis Coloring. Coloring Agents. Resumo Restauracoes provisorias sao de grande importância para obtencao de sucesso no decorrer e finalizacao de reabilitacoes dentarias. Frente as substâncias que transitam pela cavidade oral, a estabilidade de cor torna-se fundamental para obtencao de exito durante seu uso, principalmente pela manutencao da estetica. O objetivo do estudo foi avaliar a influencia das solucoes de consumo rotineiro na alteracao de cor de dois materiais utilizados na confeccao de restauracoes provisorias, comparando a estabilidade da resina acrilica com a resina bisacrilica. Para a pesquisa foram confeccionadas 60 amostras, sendo 30 de resina acrilica convencional (DencorLay, Classico Ind. E Com., Sao Paulo, SP, Brasil) e 30 de resina bisacrilicas Protemp 4 (3M ESPE, St. Paul, MN, EUA). As amostras foram divididas em 3 grupos (n=10) de acordo com o meio de imersao: agua destilada (controle), Cola-Cola® e Cafe. A avaliacao da alteracao de cor (ΔE) foi avaliada de acordo com a diferenca da tomada de cor inicial e final (apos 7 dias de imersao) atraves do aparelho espectrofotometro (Vita Easyshade Advance 4.0; Vita-zahnfabrik). Os resultados mostraram que as solucoes apresentaram significativo potencial de manchamento, e que o cafe foi o que proporcionou a maior alteracao de cor para ambas as resinas testadas (p<0,05). Independente do meio de imersao, a resina bisacrilica apresentou os maiores valores de ΔE. Atraves dos resultados obtidos, conclui-se o cafe tem alto potencial de manchamento sobre os materiais provisorios, e que a resina bisacrilica apresenta uma menor estabilidade de cor comparada com a resina acrilica. Palavras-chave: Restauracao Dentaria Temporaria. Resinas Acrilicas. Polimetil Metacrilato.