Journal of Prosthetic Dentistry

Statement of problem Much dissatisfaction with the color instability and reduced lifetime of extraoral maxillofacial prostheses due to degradation has been reported. Purpose The purpose of this study was to compare the effect of a UV mineral-based light protecting agent (LP) on the color stability of pigmented maxillofacial silicone elastomer MDX-4210/Type A after artificial aging to 2 widely used opacifiers. Material and methods Forty-five groups were established (n=225 total). Three different types of opacifiers (LP, titanium white dry pigment [TW], or silicone intrinsic white [SW]) were added to silicone MDX-4210/type A at 3 concentrations (5%, 10%, or 15%) and subsequently combined with each of 5 colors (no pigments [control], red, blue, yellow, or mixed pigments). Artists' oil pigment was used with LP and TW, while intrinsic silicone pigment was used to color SW. Before and after an energy exposure of 450 kJ/m 2 Chu CC Fischer TE Evaluation of sunlight stability of polyurethane elastomers for maxillofacial use. I. J Biomed Mater Res. 1978; 12: 347-359 Crossref PubMed Scopus (15) Google Scholar , CIE L*a*b* values were measured with a spectrophotometer. The CIELAB 50:50% perceptibility (ΔE*=1.1) and acceptability threshold (ΔE*=3.0) were used to interpret color changes (ΔE*). Color differences after aging were subjected to 3-way ANOVA. Means were compared by the Fisher PLSD intervals at α=.05. Results The ΔE* values of all groups were below the acceptability threshold of ΔE*=3.0, except for the control group of SW at 10%, which showed the greatest color change (ΔE*=3.1). When mixed pigment groups were considered, at 5% concentration, LP showed the smallest color change, followed by SW and TW (P<.05); at 10%, no significant differences among the 3 opacifiers were noted (P>.05); at 15%, LP showed the smallest color change, followed by TW and SW (P<.05). Conclusions All 3 opacifiers at all concentrations protected pigmented silicone MDX4-4210/Type A from color degradation. The LP group showed the smallest color ...

Effect of opacifiers and UV absorbers on pigmented maxillofacial silicone elastomer, part 1: Color stability after artificial aging