The Prevalence of Tooth Discolouration in China

Objectives: To determine the prevalence of tooth discolouration, self-satisfaction with tooth colour, and correlation with socio-demographic factors in adults and teenagers in Chengdu, China. Methods: A cross-sectional survey was performed using a multistage random probability sample. Tooth colour was measured on the maxillary central incisors using a colorimeter. Tooth discolouration was determined according to the discolouration level figure and evaluation criteria. Self-satisfaction with tooth colour was assessed on a five-point qualitative scale. Data were coded and analyzed using SPSS software. Multiple linear regression analysis was used to assess the socio-demographic variables impacting tooth colour, and multiple logistic regression analysis was used to examine the association between socio-demographic variables and self-satisfaction with tooth colour. Chi-square tests were conducted to examine the relationship between objective tooth discolouration and subjective tooth colour perception. Results: A total of 405 Chinese adults and teenagers participated in this study. The mean L*a*b* values were 70.67 (SD 1.91), 4.29 (SD 2.05), and 17.51 (SD 4.13), respectively. Age and sex were the most important factors impacting tooth colour (P < 0.05). About half of the study population (48.9%) suffered from some tooth discolouration, and 52.6% were dissatisfied with their tooth colour. Education and smoking were significant factors affecting self-satisfaction with tooth colour (P < 0.05). Conclusions: Tooth discolouration is common among the Chinese, and many Chinese are dissatisfied with their tooth colour. We suggest that a further increase in the demand of tooth colour improvement is likely. Key words: tooth colour, discolouration, dental perception