Lath D L, Wildgoose D G, Guan Y H, Lilley T H, Smith R N, Brook A H
School of Clinical Dentistry, University of Sheffield, United Kingdom.
J Clin Dent. 2007;18(1):17-20.
To assess tooth whiteness clinically using an image analysis system and a whiteness algorithm to compare with visual shade matching.
Images of the maxillary anterior teeth of 20 subjects were obtained using an image analysis system adapted for tooth whiteness measurement. Red, green, and blue values from each image, and Commision Internationale de l'Eclairage whiteness index (CIE WI) values were calculated. A visual shade match was also carried out using a Vitapan 3D Master 26-tab shade guide.
The range of CIE WI values for image analysis and visual shade matching was 32.86-85.91 and 32.68-79.84, respectively. Limits of agreement between methods were +17.71 and -14.60 CIE WI units. The 95% confidence interval of the difference was calculated as -0.176 to +3.083. A two-tailed Student t-test with a 95% confidence level showed significant differences (p = 0.028) between the paired CIE WI values of each tooth for the two measurement techniques. As the accuracy and reliability of the image analysis system was found to be high in previous in vitro studies, the differences between the two methods were probably related to the inherent subjectivity of visual shade matching.
The adapted digital image analysis system could be used as an alternative to, or in conjunction with visual shade matching.
使用图像分析系统和白度算法进行临床牙齿美白评估，以与视觉比色法进行比较。
使用适用于牙齿美白测量的图像分析系统获取20名受试者上颌前牙的图像。计算每张图像的红、绿、蓝值以及国际照明委员会白度指数（CIE WI）值。还使用VitaPan 3D Master 26色比色板进行视觉比色。
图像分析和视觉比色的CIE WI值范围分别为32.86 - 85.91和32.68 - 79.84。两种方法之间的一致性界限为+17.71和 - 14.60 CIE WI单位。差异的95%置信区间计算为 - 0.176至+3.083。在95%置信水平下的双尾Student t检验显示，两种测量技术对每颗牙齿的配对CIE WI值之间存在显著差异（p = 0.028）。由于在先前的体外研究中发现图像分析系统的准确性和可靠性较高，两种方法之间的差异可能与视觉比色法固有的主观性有关。
适配的数字图像分析系统可作为视觉比色法的替代方法或与之结合使用。
