Objective: To study the color distribution space of natural anterior tooth crowns of people in southwest China and effects of sex and age on tooth color.
Methods: The subjects studied consisted of 162 persons aged from 20 to 73 years and born in southwest China. A total of 1,944 healthy anterior teeth were measured in-vivo with a fiber-optical spectrophotometry system.
Results: Statistical analysis showed that the color distribution space of Chinese tooth crowns was wide. The value of L* varied from 42.383 to 67.428, the value of a* from -4.750 to 1.371, the value of b* from 1.88 to 20.268, the value of x from 0.298 to 0.393, the value of y from 0.332 to 0.392, and the value of Y from 19.383 to 34.025. The color difference between the upper and lower limits of 95% confidence was 31.667 CIE delta E units. The difference in colorimetry between male and female was not significant. The results showed that in three sections of teeth (incisal, middle and cervical) the values of L* and a* were negatively related to age (r < 0, P < 0.01); the value of b* was positively related to age just at the cervical and middle sites of teeth (r > 0, P < 0.01) and was not related to age at the incisal site of teeth (P > 0.05).
Conclusion: The color distribution space of Chinese anterior tooth crowns is wide. There is no difference in the anterior tooth color between male and female subjects. The values of L* and a* and negatively related to age except the value of b*.