四环素着色前牙色度学分布特征的检测分析

Clinical analysis of colour distribution in tetracycline teeth

目的研究四环素着色前牙色度学分布规律和特征及与正常前牙色度分布的差别。方法收集四环素着色牙患者142例,468颗四环素着色前牙及100例200颗正常前牙,采用国际照明委员会推荐的CIE-1976Lab表色系统,用ShadeEye-NCC电脑比色仪测定其色度学各要素Lab值,计算其饱和度Cab、色相角hab°。采用SAS6.12统计软件包进行描述性统计和t检验、duncan检验。结果四环素着色前牙色度总体分布为L值42.33～77.00,a值-0.6～9.6,b值2.67～31.5,饱和度(Cab)5.24～31.89,色相角(hab°)38.62°～95.47°;与正常牙相比,四环素着色牙较灰暗,色相偏红(P<0.01),饱和度(Cab)无统计学差异(P>0.05)。对同一患者同一象限前牙比较,亮度上尖牙比中切牙、侧切牙偏暗(P<0.01),色相上尖牙比侧切牙偏红(P<0.05);其余两两比较均无统计学差异(P>0.05),3者在饱和度上均无差异,中切牙和侧切牙在色度三要素上均无统计学差异。结论四环素着色牙色度分布较为松散,色度学各要素分布范围广,总体较正常牙偏灰暗,偏红。

PURPOSE： To analyze the colour range and distribution of tetracycline teeth, and the difference from normal teeth. METHODS： 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 （hab°） 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. RESULTS： The range of L, a, b Cab, hab° of tetracycline teeth was 42.33-77.00,-0.6-9.6,2.67-31.5,5.24-31.89,38.62°-95.47°, respectively. Significant difference of L value and hue （hab°） 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 （hab°） 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. CONCLUSIONS： 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 Project （Grant No.T0202） and Key Research Project of Shanghai Municipal Education Commission （Grant No.02BZ33）.