Rueggeberg F A, Harvey D K, Evans A L
School of Dentistry, Medical College of Georgia, Augusta 39012-1264.
Am J Dent. 1991 Aug;4(4):171-6.
The purpose of this study was to determine the color changes that arise from post-cure heat treatment of selected light-cured resin composites by using colorimetric as well as observational methods. Brands of composite were selected that were solely Bis-GMA-based and Bis-GMA/urethane based. These materials also represented a range of filler content (low, medium, and high). The RGB values of cured resin discs were obtained immediately after light-curing as well as after a 5-minute post-cure heat exposure. The range of post-cure temperature was from 100-300 degrees C in 25 degrees C increments. The mean delta L*, delta a*, delta b* and delta E* were determined from red, green and blue data using triplicate replications for each heating condition. Twenty-one observers were asked to determine if the randomly arranged post-cure heated specimens differed in color from the unheated, cured control specimen for each brand. The results indicate that a delta E* value of approximately 3 resulted in greater than 50% of the observers noting a color difference between the post-cure heated specimen and the unheated control. The degree of color change was influenced more by the amount of resin content in the composite systems rather than by the particular resin composition. Microfill resins showed greater potential for color change than did the other types of materials. If clinicians are considering using conventional light-cured composite materials for inlays, the choice of material as well as the post-cure temperature will influence the ability to match the inlay with the original shade of composite selected.
本研究的目的是通过比色法和观察法来确定所选光固化树脂复合材料后固化热处理引起的颜色变化。选择了仅基于双酚A-甲基丙烯酸缩水甘油酯（Bis-GMA）和基于Bis-GMA/氨基甲酸酯的复合材料品牌。这些材料还代表了一系列填料含量（低、中、高）。在光固化后以及5分钟的后固化热暴露后，立即获得固化树脂圆盘的RGB值。后固化温度范围为100 - 300摄氏度，以25摄氏度递增。对于每种加热条件，使用一式三份的重复样本，从红色、绿色和蓝色数据中确定平均ΔL*、Δa*、Δb和ΔE。要求21名观察者确定每个品牌的后固化加热标本与未加热的固化对照标本在颜色上是否存在差异，这些标本是随机排列的。结果表明，大约3的ΔE*值会使超过50%的观察者注意到后固化加热标本与未加热对照之间存在颜色差异。颜色变化的程度受复合体系中树脂含量的影响更大，而不是受特定树脂组成的影响。微填料树脂比其他类型的材料显示出更大的颜色变化潜力。如果临床医生考虑使用传统光固化复合材料制作嵌体，材料的选择以及后固化温度将影响嵌体与所选原始复合树脂颜色匹配的能力。
