Ruan Dan-ping, Qian Cheng-hui, Zhang Xiu-yin, Bian Yi-ming, Yu Yi-ming, Yu Wei-qiang
Department of Prosthodontics, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China.
Shanghai Kou Qiang Yi Xue. 2006 Dec;15(6):567-70.
To analyze the colour range and distribution of tetracycline teeth, and the difference from normal teeth.
142 cases with 468 anterior tetracycline teeth and 100 cases with 200 normal anterior teeth were collected. The color was measured by a computer-aided Shade-Eye NCC colorimeter, and expressed in terms of 3 coordinate values (L,a,b) of the CIE-1976-Lab color system. Chroma (Cab)and hue (h(ab) degrees)were calculated according to the value of a and b. The data were analyzed with SAS6.12 software package for description, Student's t test and Duncan test.
The range of L, a, b Cab, h(ab) degrees of tetracycline teeth was 42.33-77.00, -0.6-9.6, 2.67-31.5, 5.24-31.89, 38.62 degrees-95.47 degrees, respectively. Significant difference of L value and hue (h(ab) degrees) was found between tetracycline teeth and normal teeth (P < 0.01), which indicated that tetracycline teeth were darker and redder than normal teeth. There was no difference of chroma (Cab) between tetracycline teeth and normal teeth (P > 0.05). Moreover there was significant difference of L value between canine and central incisor, and of H value (h(ab) degrees) between canine and lateral incisor in tetracycline teeth, which indicated that canine was darker and redder than incisor, and redder than lateral incisor, but there was no significant difference in chroma (Cab) among all anterior teeth and no difference in L, a, b between central incisor and lateral incisor.
The study showed the color distribution of tetracycline teeth was wider and more dispersive than normal teeth, and much darker and redder than normal teeth. Supported by Shanghai Leading Academic Discipline
分析四环素牙的颜色范围及分布情况，以及与正常牙齿的差异。
收集142例共468颗前牙四环素牙病例和100例共200颗正常前牙病例。采用电脑辅助的Shade-Eye NCC色差仪测量颜色，以CIE-1976-Lab颜色系统的3个坐标值（L、a、b）表示。根据a和b值计算彩度（Cab）和色调（h(ab)度）。使用SAS6.12软件包对数据进行描述性分析、Student's t检验和Duncan检验。
四环素牙的L、a、b、Cab、h(ab)度范围分别为42.33 - 77.00、-0.6 - 9.6、2.67 - 31.5、5.24 - 31.89、38.62度 - 95.47度。四环素牙与正常牙齿之间L值和色调（h(ab)度）存在显著差异（P < 0.01），表明四环素牙比正常牙齿颜色更深且更偏红。四环素牙与正常牙齿之间彩度（Cab）无差异（P > 0.05）。此外，四环素牙中尖牙与中切牙之间L值存在显著差异，尖牙与侧切牙之间H值（h(ab)度）存在显著差异，表明尖牙比切牙颜色更深且更偏红，比侧切牙更偏红，但所有前牙之间彩度（Cab）无显著差异，中切牙与侧切牙之间L、a、b无差异。
研究表明，四环素牙的颜色分布比正常牙齿更宽且更分散，比正常牙齿颜色深得多且更偏红。由上海重点学科资助
