Metameric effect between natural teeth and the shade tabs of a shade guide
Metameric effect between natural teeth and the shade tabs of a shade guide
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DOI：
10.1111/j.1600-0722.2010.00730.x
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发表时间：
2010-06-01
影响因子：
1.9
通讯作者：
Hassel, Alexander J.
中科院分区：
文献类型：
--
作者：
Corcodel, Nicoleta;Helling, Stephan;Hassel, Alexander J.
本研究的目的是评估异色效应，即牙齿和阴影标签的颜色对所使用的光源的依赖。使用口腔内分光光度计（VITA Easyshade）测量37名参与者的49颗牙齿的颜色以及3D-Master （VITA Zahnfabrik；颜色匹配Delta E(ab)< 2）的相应色卡的颜色。记录光谱反射数据（400 ~ 700 nm）。国际照明委员会（CIE）计算了D65（参考日光）、a（白炽灯）和TL84（商店/办公室灯）作为参考光源的l *a*b*值。计算改进的同色指数（Mod-M）和色相角比，以表示相对于D65照明下观察到的牙齿和标签颜色差异。牙齿和标签的Mod-M大于统一（表明相对于D65有更大的色差），a为57.1%，TL84为49.3%。使用测试光源获得的牙齿和标签的色度角比与使用标准光源D65获得的色度角比不同。如果在日光下进行齿形和遮光片匹配，则在其他照明条件下的色差可能不一样，从而导致在这些条件下的可察觉甚至不可接受的色差。
The objective of this study was to evaluate metameric effects, that is, the dependence of the colours of teeth and shade tabs on the illuminant used. The colours of 49 teeth of 37 participants and of the corresponding shade tabs of the 3D-Master (VITA Zahnfabrik; colour match Delta E(ab)< 2) were measured using an intra-oral spectrophotometer (VITA Easyshade). Spectral reflectance data (from 400 to 700 nm) were recorded. Commission Internationale de l'Eclairage (CIE) L*a*b* values were calculated for D65 (reference daylight), A (incandescent light), and TL84 (store/office light) as reference illuminants. A modified metamerism index (Mod-M) and hue-angle ratios were calculated to express differences between tooth and tab colour relative to the difference observed under D65 illumination. The Mod-M for teeth and tabs was greater than unity (indicating a greater colour difference relative to D65) by 57.1% for A and by 49.3% for TL84. Hue-angle ratios of teeth and tabs using the test illuminants were different from those obtained using the standard illuminant D65. If teeth and shade tab matching is conducted using daylight illumination, the colour difference may not be the same under other lighting conditions, leading to perceptible, or even unacceptable, colour differences under these conditions.