Department of Dental Materials and Prosthodontics, Araçatuba Dental School, UNESP, Araçatuba, Brazil.
J Prosthodont. 2011 Apr;20(3):205-8. doi: 10.1111/j.1532-849X.2010.00657.x. Epub 2010 Nov 15.
The aim of this study was to evaluate the influence of two pigments (ceramic powder and oil paint) and one opacifier (barium sulfate) on the color stability of MDX4-4210 facial silicone submitted to accelerated aging.
Sixty specimens of silicone were fabricated and divided into six groups--colorless (G1), colorless with opacifier (G2), ceramic (G3), ceramic with opacifier (G4), oil (G5), oil with opacifier (G6). All replicas were submitted to accelerated aging for 1008 hours. The evaluations of chromatic alteration through visual analysis and reflection spectrophotometry were carried out initially and after 252, 504, and 1008 hours of aging. The results were submitted to ANOVA and Tukey's test at 5% level of significance.
All groups exhibited chromatic alteration (ΔE > 0); however, this color alteration was not perceptible through visual analysis of the color. The pigmented groups with opacifier presented the lowest ΔE values, with a statistical difference from the other groups. For the groups without opacifier, the group pigmented with oil paint exhibited the lowest ΔE values in the different aging periods, with a statistical difference. Accelerated aging generated significant chromatic alterations in all groups after 252 hours, except for the colorless and oil groups, both with opacifier (G2 and G6).
The opacifier protects facial silicones against color degradation, and oil paint is a stable pigment even without addition of opacifier.
本研究旨在评估两种颜料（陶瓷粉和油画颜料）和一种不透光剂（硫酸钡）对 MDX4-4210 面部硅橡胶在加速老化后颜色稳定性的影响。
制备 60 个硅橡胶样本，并将其分为 6 组——无色（G1）、带不透光剂的无色（G2）、陶瓷（G3）、带不透光剂的陶瓷（G4）、油（G5）、带不透光剂的油（G6）。所有复制品均进行加速老化 1008 小时。通过视觉分析和反射分光光度法对颜色变化进行初始评估和老化 252、504 和 1008 小时后的评估。结果采用方差分析和 Tukey 检验，置信度为 5%。
所有组均发生颜色变化（ΔE＞0）；然而，通过颜色的视觉分析，这种颜色变化是不可察觉的。带不透光剂的着色组呈现出最低的ΔE 值，与其他组有统计学差异。对于不带不透光剂的组，在不同老化时期，油颜料着色组呈现出最低的ΔE 值，具有统计学差异。在 252 小时后，除了带不透光剂的无色组和油组（G2 和 G6）外，所有组在加速老化后均产生了显著的颜色变化。
不透光剂可保护面部硅橡胶免受颜色降解，即使不添加不透光剂，油画颜料也是一种稳定的颜料。
