Methods: Eight groups of MDX 4-4210 (medical grade)and VST-50 (food grade)elastomers were prepared and mixed with yellow silicone fluid colorant. The specimens were exposed to 4 conditions: control (23 °C, 55% RH), heat (37 °C, 0% RH), humidity (37 °C, 100% RH) and UV-light (320-400 nm, 8 watt, 23 °C) for a period of 0, 240, 720, 1440, and 3528 hours. CIE L*a*b* values were measured by spectrophotometer. The color differences (ƒxE*) of both facial silicones were subjected to three-factor ANOVA with repeated measures. Mean values were compared with Game-Howell intervals calculated at the 0.05 significance level.
Results: This study revealed that environmental effects and exposure times influenced the change of color (ƒxE*) of both facial silicone at a level of statistical significance (P<0.05). UV light and moisture had the most effect on the change of color in both silicones. VST-50 changed color faster than MDX4-4210.
Conclusions: The different environmental variables and exposure times affected color stability of both MDX 4-4210 and VST-50. Because of a limitation to one colorant, further studies would extend to several types of colorants to determine the influence of colorants for both silicones to get the beneficial information to select the appropriate silicone for clinical use.