Lee Yong-Keun
Department of Dental Biomaterials Science, Dental Research Institute, College of Dentistry, Seoul National University, 28 Yeongeon-dong, Jongro-gu, Seoul, Republic of Korea.
Dent Mater. 2007 Apr;23(4):492-7. doi: 10.1016/j.dental.2006.03.004. Epub 2006 Apr 24.
The objectives were to evaluate the difference in the translucency parameter (TP) by the illuminants, to determine the correlation between the contrast ratio (CR) and three TP values relative to the illuminants, and to measure the correlation between the differences in TP (DeltaTP) and color (DeltaE(ab)*) by the illuminants based on dental porcelain and porcelain repairing resin composites.
Color and spectral reflectance of three shades of one dental porcelain and three porcelain repairing resin composites were measured before and after thermocycling for 3000 cycles relative to the CIE standard illuminants D65, A and F2 over a white and a black backgrounds. Specimen was 1.8mm in thickness after polishing. CR was calculated, and the differences in TP and color caused by the change of illuminants were compared. Three-way analysis of variance by the material (porcelain or resin composite), shade and illuminant was used to compare differences (alpha=0.05).
The TP value was influenced by the illuminant (p<0.05), and the TP values relative to the illuminants A and F2 were higher than those relative to D65. The correlation coefficients between the CR and three TP relative to the three illuminants were around -0.95. Color difference was positively correlated with the difference in translucency in resin composites (r=0.65 between A and D65 and 0.47 between F2 and D65), but was negatively correlated in porcelain (r=-0.37 between A and D65 and -0.69 between F2 and D65).
Difference in translucency by illumination should be considered when matching shade of porcelain and repairing resin composite.
评估不同光源下的半透明参数（TP）差异，确定对比度（CR）与相对于光源的三个TP值之间的相关性，并基于牙科陶瓷和陶瓷修复树脂复合材料测量光源引起的TP差异（ΔTP）与颜色差异（ΔE(ab)*）之间的相关性。
相对于CIE标准光源D65、A和F2，在白色和黑色背景下，对一种牙科陶瓷的三种色号以及三种陶瓷修复树脂复合材料进行3000次热循环前后的颜色和光谱反射率测量。抛光后试样厚度为1.8mm。计算CR，并比较光源变化引起的TP和颜色差异。采用材料（陶瓷或树脂复合材料）、色号和光源的三因素方差分析来比较差异（α = 0.05）。
TP值受光源影响（p<0.05），相对于光源A和F2的TP值高于相对于D65的TP值。相对于三种光源，CR与三个TP之间的相关系数约为 -0.95。树脂复合材料中颜色差异与半透明差异呈正相关（A与D65之间r = 0.65，F2与D65之间r = 0.47），而在陶瓷中呈负相关（A与D65之间r = -0.37，F2与D65之间r = -0.69）。
在匹配陶瓷和修复树脂复合材料的色号时，应考虑光照引起的半透明差异。
