离体天然牙颜色的色度学测量与分析

Chroma study of natural tooth crown in vitro

目的:通过对离体天然牙牙冠颜色测量和分析,探讨年龄对天然牙颜色参数的影响以及二者间的相关关系。方法:采用PR-650光谱扫描色度仪、Photo Research颜色分析软件和CIE1976 L*a*b*标准色度系统对267颗离体天然牙进行切、中、颈1/3三个位点的测量。结果:①不同年龄段不同牙位的颜色参数跨度大,均数变化明显;②L*值与年龄呈负相关(p<0.05),随年龄增长明度降低,牙色变暗;但磨牙的颈部表现不明显(p>0.05)。③a*在不同的牙位表现不一致:前牙与年龄呈明显的负相关关系(p<0.05);前磨牙则变化不一致,切端呈现负相关(p<0.05),而在中部和颈部呈现正相关,且颈部相关性明显(p<0.05);磨牙与年龄呈正相关,1/3具有明显相关关系(p<0.05)④b*与年龄呈正相关(p<0.05),随年龄的增长,切、中、颈1/3的颜色偏黄,但前磨牙的切1/3表现不明显(p>0.05)。结论:天然牙的颜色参数随年龄的增长明度下降,颜色变黄,但是红绿色相变化在不同牙位的三个部位是不完全一致的。

To investigate the correlation between tooth crown chroma parameter and age by measuring the tooth crown colour. Method： In present study, 267 natural teeth were measured quantitatively with a spectrocolorimeter （PR-650） in three positions in vitro.The selected colour system was 1976CIE L＊a＊b＊ system. Result： 1. The L＊a＊b parameter of anteriors ,bicuspids and molars was different in longitudinal （cervical, middle, incisal ）.2. Statistical analysis showed that the value of L＊ was related to age negatively, with the highest average value of L＊ of young adult among the three groups; the adult＇s was higher than the aged group. The value of b＊ was related to age positively, with the highest average value of b＊ of the aged group among the three measured groups; The value of a＊ has the different change tendency both among different groups and different teeth positions. Conclusion：The values of L＊ was negatively related to age. The value of b＊was positively to age. Natural tooth colour has a significant tendency to increase with the age of the subject, generally becoming darker and more yellow. But the value of a＊ was not certain.