Rugh E H, Johnston W M, Hesse N S
US Air Force, Seymour-Johnson AFB, North Carolina.
Int J Prosthodont. 1991 Nov-Dec;4(6):569-76.
The effect of opacity on the colorimetric responses of large-area and small-area colorimeters was determined using an elastomer intended for maxillofacial prosthetics use and containing various pigments at different concentrations. Opacity was determined by calculating the contrast ratio of 2-mm-thick specimens against black and white backings, using Kubelka-Munk analyses to correct for thickness and backing color variations. The measure of comparison of the two colorimeters was the relative difference in tristimulus reflectance, with the tristimulus reflectance of the large-area colorimeter as the basis of the relative difference. A significant quadratic relationship was found between contrast ratio and the relative difference in tristimulus reflectance. This relationship may be used to describe opacity without the need to make optical observations or measurements of a thin layer of material on contrasting backings. The small-area colorimeter produced color parameters that are a measure of the combined effects of both color and opacity. The importance of beam size considerations of optical measuring devices for translucent natural and prosthetic materials was emphasized.
使用一种用于颌面修复的弹性体来测定不透明度对大面积和小面积比色计比色响应的影响，该弹性体含有不同浓度的各种色素。通过计算2毫米厚的试样与黑色和白色背景的对比度来确定不透明度，并使用库贝尔卡-蒙克分析法校正厚度和背景颜色变化。两种比色计的比较指标是三刺激值反射率的相对差异，以大面积比色计的三刺激值反射率作为相对差异的基础。发现对比度与三刺激值反射率的相对差异之间存在显著的二次关系。这种关系可用于描述不透明度，而无需对对比背景上的薄层材料进行光学观察或测量。小面积比色计产生的颜色参数是颜色和不透明度综合效应的一种度量。强调了光学测量设备光束大小对于半透明天然材料和修复材料的重要性。
