The color stability of maxillofacial elastomers in combination with UV inhibitors

The purpose of this study was to investigate the effectiveness of selected UV additives in preventing color fading of maxillofacial silicone elastomers. Two addition-type platinum cured silicone elastomers, (silicone 2186 and silicone 2000, Factor II, Inc.), were combined with red liquid pigment (Intrinsic II, Factor II, Inc.), and one of three UV additive powders (Tinuvin 622, Tinuvin 328, and Chimassorb 81). Control samples that did not contain any additives were also created. Sample disks were fabricated and either stored in darkness or exposed to UVB light. L*a*b* color measurements were recorded at baseline, 900 hours, and 1200 hours using a color reflectance spectrophotometer. Statistical differences were found in the AE based on additive type at 1200 hours. Most significant differences were identified in the individual ΔL, Δa, and Δb values. Overall, samples combined with Tinuvin 622 did not tend to have drastic changes in the ΔL, Δa, and Δb readings, and remained fairly stable over time and exposure to UVB. Samples containing Tinuvin 328 demonstrated the most drastic changes in ΔL, Δa, and Δb readings over time and exposure to UVB. Samples containing Chimassorb 81 presented results that fell in between the Tinuvin 622 and Tinuvin 328 readings.