Over L M, Andres C J, Moore B K, Goodacre C J, Muñoz C A
Indiana University School of Dentistry, Indianapolis, USA.
J Prosthodont. 1998 Dec;7(4):237-49. doi: 10.1111/j.1532-849x.1998.tb00212.x.
To determine if using CIE Lab* color measurements of white facial skin could be correlated to those of silicone shade samples that visually matched the skin. Secondly, to see if a correlation in color measurements could be achieved between the silicone shade samples and duplicated silicone samples made using a shade-guide color formula.
A color booth was designed according to ASTM specifications, and painted using a Munsell Value 8 gray. A Minolta colorimeter was used to make facial skin measurements on 15 white adults. The skin color was duplicated using custom-shaded silicone samples. A 7-step wedge silicone shade guide was then fabricated, representing the commonly encountered thicknesses when fabricating facial prostheses. The silicone samples were then measured with the Minolta colorimeter. The readings were compared with the previous Lab* readings from the corresponding patient's skin measurements, and the relative color difference was then calculated. Silicone samples were fabricated and analyzed for three of the patients to determine if duplication of the visually matched silicone specimen was possible using the silicone color formula, and if the duplicates were visually and colorimetrically equivalent to each other. The color difference Delta E and chromaticity was calculated, and the data were analyzed using a coefficient-of-variation formula expressed by percent. A Pearson Product Moment Correlation Coefficient was performed to determine if a correlation existed between the skin and the silicone samples at the p < or = .05 level.
The highest correlation was found in the b* dimension for silicone thicknesses of 1 to 4 mm. For silicone thicknesses of 6 to 10 mm, the highest correlation was found in the L* dimension. All three dimensions had positive correlations (R2 > 0), but only the 1-mm and 4-mm b* readings were very strong. Patient and silicone Lab* measurement results showed very little change in the a* axis, while the L* and b* measurements showed more change in their numbers, with changes in depth for all patient silicone samples. Delta E numbers indicated the lowest Delta E at the 1-mm depth and the highest Delta E at the 10-mm depth. All duplicated samples matched their original silicone samples to a degree that visual evaluation could not distinguish any color differences. Using volumetric measurements, a shade guide was developed for all 15 patients.
There was good correlation between the patient's colorimeter measurements and the silicone samples, with the b* color dimension the most reproducible, followed by the L* and the a*. Silicone samples at 6, 8, and 10 mm matched the patient the best, and this study showed that silicone samples can be duplicated successfully if a good patient-silicone match is obtained. Rayon flocking fibers and liquid makeup are effective at matching facial prostheses and can be used to develop a simple shade guide for patient application.
确定白色面部皮肤的CIE Lab*颜色测量值是否与视觉上匹配皮肤的硅胶色样的测量值相关。其次，查看硅胶色样与使用色标颜色配方制作的复制硅胶样品之间是否能实现颜色测量的相关性。
根据ASTM规范设计了一个颜色 booth，并使用孟塞尔值8的灰色进行粉刷。使用美能达色度计对15名白人成年人的面部皮肤进行测量。使用定制着色的硅胶样品复制皮肤颜色。然后制作了一个7步楔形硅胶色标，代表制作面部假体时常见的厚度。接着用美能达色度计测量硅胶样品。将读数与相应患者皮肤测量先前的Lab*读数进行比较，然后计算相对色差。对三名患者的硅胶样品进行制作和分析，以确定使用硅胶颜色配方是否能够复制视觉上匹配的硅胶标本，以及复制件在视觉和色度上是否彼此等效。计算色差ΔE和色度，并使用以百分比表示的变异系数公式分析数据。进行Pearson积矩相关系数分析，以确定在p≤0.05水平时皮肤和硅胶样品之间是否存在相关性。
在1至4毫米的硅胶厚度下，b维度的相关性最高。对于6至10毫米的硅胶厚度，L维度的相关性最高。所有三个维度都呈正相关（R2>0），但只有1毫米和4毫米的b读数相关性非常强。患者和硅胶的Lab测量结果显示，a轴变化很小，而L和b*测量值在数值上变化更大，所有患者硅胶样品的深度都有变化。ΔE数值表明，在1毫米深度时ΔE最低，在10毫米深度时ΔE最高。所有复制样品在一定程度上与原始硅胶样品匹配，视觉评估无法区分任何颜色差异。使用体积测量法，为所有15名患者开发了一个色标。
患者的色度计测量值与硅胶样品之间存在良好的相关性，b颜色维度的再现性最高，其次是L和a*。6毫米、8毫米和10毫米的硅胶样品与患者匹配最佳，本研究表明，如果获得良好的患者-硅胶匹配，硅胶样品可以成功复制。人造丝植绒纤维和液体化妆品在匹配面部假体方面有效，可用于为患者应用开发一个简单的色标。
