Optical properties of pigmented polydimethylsiloxane prosthetic elastomers: effect of 'outdoor' and 'indoor' accelerating aging.

摘要

OBJECTIVES: Optical properties of facial prosthetic elastomers undergo significant changes mainly due to aging. The resulting changes in their appearance are the main reasons of facial prosthesis' replacement. PURPOSE: The purpose of this study was to evaluate changes in the translucency parameter (TP) and color (DeltaE*) of polydimethylsiloxane (PDMS) maxillofacial elastomers after exposure to 3 different aging conditions (time passage, accelerated "outdoor" aging, and accelerated "indoor" aging). MATERIALS AND METHODS: The PDMS prosthetic elastomers tested in this study were low- (LTV) and high-temperature vulcanized (Episil and Mollomed, respectively) in various shades. Color changes (DeltaE*) and translucency parameter (TP) were determined in the CIE L*a*b* system using a tristimulus colorimeter. Data were subjected to 2-way analysis of variance followed by Tukey post hoc test. In addition, TP values were analyzed by paired t tests. The significance level of alpha = 0.05 was set for all tests. RESULTS: Translucency parameter values for most samples were significantly changed after aging, and DeltaE* values were characterized as unacceptable. Both aging procedure and material type affected the changes that occurred. Moreover, dark-shaded samples of both silicone materials revealed significant changes in TP values before and after aging. DeltaE* was not significantly different among the same material samples but had significant differences between the 2 materials (Episil and Mollomed). Time passage did not significantly affect TP values contrary to the other 2 accelerated aging procedures. Between outdoor and indoor aging, no significant differences were detected. CONCLUSIONS: Accelerated outdoor and indoor aging caused significant changes in DeltaE* and TP values. Significant changes were also detected between material types.