Objective

To evaluate color and whiteness changes of natural teeth under nine white LED illuminants recently proposed by CIE.

Methods

From spectral reflectance factors of 36 caries-free upper central incisors, corresponding colors under illuminant D65 and CIE 1931 standard colorimetric observer were computed for all tested illuminants, using the chromatic adaptation transform CAT16. Color differences (CIELAB and CIEDE2000 units) and whiteness (${WI}_D$ and ${WI}_O$ indices) from teeth illuminated by CIE standard illuminants (D65 and A) and white LED illuminants were calculated. The appearance of 630 pairs of teeth under all illuminants was also evaluated.

Results

Color gamuts from 36 teeth under tested illuminants showed similar volume and shape in CIELAB color space, but their centers of gravity changed in many different directions with respect to colors under D65 or A illuminants: Considering colors under D65/A, color shifts produced by white LED illuminants were in the ranges 2.0–8.6/1.1–7.0 CIELAB units (1.4–8.2/0.6–6.8 CIEDE2000 units). Average ${WI}_D$ and ${WI}_O$ values for the 36 teeth under different illuminants ranged from −5.8 to +19.3 and from −7.7 to +11.1, respectively. Considering 630 pairs of teeth, average color differences (mainly lightness differences) were below 0.5 CIELAB units (0.3 CIEDE2000 units), and average whiteness differences ranged from 8.1 to 10.7 for ${WI}_D$ (23.4–25.1 for ${WI}_O$).

Significance

Using CIE LED illuminants, most changes in color and whiteness for individual teeth were above typical threshold values of perceptibility and acceptability in dentistry. However, considering pairs of teeth, the average color and whiteness differences under all tested illuminants were very similar.

中文翻译：

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在白色发光二极管光源下测量的天然牙齿的颜色不稳定性

目的

为了评估CIE最近提出的九种白色LED光源下天然牙齿的颜色和白度变化。

方法

根据色度自适应变换CAT16，从36个无龋的上中切牙的光谱反射率中，计算出所有测试光源在D65光源和CIE 1931标准比色观察器下的对应颜色。色差（CIELAB和CIEDE2000单位）和白度（${\mathrm{w\; ^}\mathrm{一世}}_d$ 和 ${\mathrm{w\; ^}\mathrm{一世}}_{Ø}$由CIE标准光源（D65和A）和白光LED光源计算出牙齿的牙齿指数）。还评估了在所有光源下630对牙齿的外观。

结果

在测试的光源下，来自36个牙齿的色域在CIELAB颜色空间中显示出相似的体积和形状，但是它们的重心相对于D65或A光源下的颜色在许多不同的方向上发生变化：考虑到D65 / A光源下的颜色，白色产生的色移LED光源的范围为2.0–8.6 / 1.1–7.0 CIELAB单位（1.4–8.2 / 0.6–6.8 CIEDE2000单位）。平均${\mathrm{w\; ^}\mathrm{一世}}_d$ 和 ${\mathrm{w\; ^}\mathrm{一世}}_{Ø}$在不同光源下的36颗牙齿的最大齿值分别在-5.8至+19.3和-7.7至+11.1之间。考虑到630对牙齿，平均色差（主要是亮度差）低于0.5 CIELAB单位（0.3 CIEDE2000单位），并且平均白度差在8.1到10.7之间${\mathrm{w\; ^}\mathrm{一世}}_d$ （对于23.4–25.1 ${\mathrm{w\; ^}\mathrm{一世}}_{Ø}$）。

意义

使用CIE LED光源时，单个牙齿的颜色和白度的大多数变化都超过了牙科可感知性和可接受性的典型阈值。但是，考虑到成对的牙齿，所有测试光源下的平均颜色和白度差异非常相似。