AVALIAÇÃO COLORIMÉTRICA E DA ESTABILIDADE DE COR DE DIFERENTES MATERIAIS RESINOSOS E ESTRATÉGIAS RESTAURADORAS APLICADAS SOBRE BASES DESCOLORIDAS

Abstract

The present study aimed to evaluate the effect of color change after using distinct restorative procedures as multilayer and single layer on color bases, as well as to evaluate color stability in restored sets. Study was divided into three stages: in the first one, 90 specimens were made and divided into 9 experimental groups (n=10). A1 shade (1mm) color restorations in multilayer (Estelite Omega and Empress Direct) and single layer (Filtek Universal, Filtek Z350XT and Vittra Unique) were developed on DA2 shade bases. In the second, 120 specimens were made and divided into 12 experimental groups (n=10). A1 shade (1mm) color restorations in dentine multilayer and enamel (Estelite Omega and Empress Direct) and in single layer (Filtek Universal, Filtek Z350XT) with and without the use of opacifying agents (Opaque and Pink Opaque), were carried out on color DC4 bases. In the third stage, specimens based on DC4 were subjected to aging in distilled water at 37ºC for 100 days. In order to evaluate color parameters, a reflection spectrophotometer with D65 illuminant was used, following CIEL*a*b* and CIEL*C*h system standarts, besides whiteness index (Wid). After aging period, new colorimetric measurements were made to evaluate color stability through ∆Eab and ∆E00. Statistical analysis was performed using ANOVA and Tukey tests, with significance of 5%. There was a significant difference among all tested levels and variables. In the first stage, Filtek Z350XT resin presented best results in L*, however it did not show the same superiority for Wid, giving way to Estelite Omega resin in greater dentin thicknesses. Results related to a*, b*, hº and C* axis showed low values among all tested groups on DA2 bases. In the second stage, the use of opacifying agents was able to increase values of L* axis, however Wid only obtained a positive value in the interaction with Pink Opaque agent. Results for b*, C* and h° axis were the same, which showed yellowing on the set in the interaction with Opaque agent, while a* axis showed variation according to coloring agent and restorative procedure. Z350XT resin was able to generate the best optical results in comparison with Estelite Omega, Empress Direct and Filtek Universal resins, which only resulted positive in the interaction with Pink Opaque agent. In the third stage, a small variation of ∆Eab and ∆E00 was observed, which presented total color variations that remained within acceptability limit. Therefore, in teeth without discoloration, Estelite Omega resin tends to present advanced colorimetric results, however its use will not result in good values for masking discolored teeth. In the present study, the use of Pink Opaque agent positively helped with masking, regardless the restorative procedure, while Opaque depends on procedure and material. Filtek Z350XT composite resin results in good masking ability regardless the use of opacifiers. All tested materials demonstrated good color stability after 100 days of aging.