Change in color of a maxillofacial prosthetic silicone elastomer, following investment in molds of different materials
PURPOSE The aim of this investigation was to explore the relationship between an objective computer measurement of color difference (ΔE) and subjective clinical opinion of a "good" color match between silicone samples and skin. MATERIALS AND METHODS In Part 1 of this study, silicone samples were colored to match the skin of 19 African-Canadian subjects based on spectrophotometric measurements and pigment formulae determined by computerized color formulation software. Four iterative samples were prepared for each subject; a ΔE value was recorded for each sample to represent the color difference between the silicone sample and skin. In this article, Part 2, five judges independently assessed the color match of the silicone samples to the skin of each of the subjects. Skin and silicone samples were rated on a five-point scale as a measure of "color match." A multivariate analysis was used to determine relationships between judges' assessments and the following variables: color difference between silicone and skin (ΔE), pigment loading, and skin characteristics (L*, a*, b*). RESULTS There was a positive correlation between judges' scores and low ΔE values for the first two samples. All judges rated the first sample a poorer color match than the fourth sample (p < 0.015). The third sample performed better overall according to judges. Increased pigment loading in the fourth sample resulted in poorer scores. A trend was observed in pigment selection based on skin values, though no significant relationships were determined. CONCLUSION Spectrophotometry and computerized color formulation technology offer an enhanced understanding of color for its artistic application in facial prosthetic treatment. While some correlation between the objective and subjective assessments of color match exist, it is not a simple relationship. Further study is required to better understand the relationship between technology and clinical perception, specifically in objective and subjective assessments of a "good" color match of silicone to skin.