Translucency parameter of colorants for maxillofacial prostheses.

The masking power of various generic, dry mineral earth, and flocking colorants dispersed in medical-grade silicone elastomer was investigated. Reflectance measurements were made by diffuse reflectance spectrophotometry using black and white backings. These data were reduced to optical scattering and absorption coefficients through the use of the Kubelka-Munk reflectance theory. The color difference between a 0.13-cm-thick layer of the colored elastomer placed on an ideal black backing and this layer on an ideal white backing was calculated and established as a translucency parameter. Using analysis of variance and stepwise comparison testing, significant differences were found among the translucency parameters of the colorants. Since these colorants differ substantially in their ability to mask underlying colors and since the translucency of maxillofacial material is an important aspect of color measurement and natural appearance, differences in these colorants go beyond their obvious differences in color.