Association between tea types and number of teeth: a cross-sectional study of the Chinese Longitudinal Healthy Longevity Survey.

BACKGROUND: Previous studies have suggested that tea consumption may have a positive impact on oral health. However, the effects of different tea types on oral health remain unclear. Therefore, this study aimed to determine the association between residual teeth and consumption habits of different types of tea (green tea, black tea, oolong tea, and scented tea) in older adults. METHODS: We conducted a secondary analysis using data from the Chinese Longitudinal Healthy Longevity Survey in 2018. In a sample of 6,387 older adults, we performed logistic regression analysis to examine the relationship between persistent tea consumption and oral health according to sex and brushing frequency. The indices for particularly healthy oral health and relative health were set at more than 20 teeth and more than 10 teeth, respectively. RESULTS: The study included 2,725 males and 3,662 females, both aged 65 and older. Among individuals with more than 20 teeth, drinking green tea significantly improved oral health in men (adjusted odds ratio [ORs]: 1.377; 95% confidence interval [CI]: 1.082-1.752) and drinking black tea significantly improved the oral health of women (ORs: 2.349, 95%CI: 1.028-5.366). In the daily brushing group, green tea had a significant beneficial effect on increasing the number of teeth in men and black tea had a significant beneficial effect in women. Among individuals with more than 10 teeth, drinking green tea significantly improved oral health in men (ORs: 1.539; 95% CI: 1.209-1.959) and drinking green tea and scented tea significantly improved the oral health of women (ORs: 1.447, 95%CI: 1.052-1.991; ORs: 1.948, 95%CI: 1.137-3.340). In the daily brushing group, consumption of green tea and black tea had significant beneficial effects on increasing the number of teeth in men, whereas that of green tea, black tea, and scented tea had significant beneficial effects in women. CONCLUSION: Long-term green tea consumption in males and black tea consumption in females were significantly associated with maintaining functional dentition (≥20 teeth). Similarly, long-term green tea consumption in males and green tea and scented tea consumption in females were associated with avoiding severe tooth loss (≥10 teeth). Furthermore, in the daily tooth brushing group, long-term consumption of black tea was associated with avoiding severe tooth loss in both sexes. However, tea consumption alone had no effect on oral health without good brushing habits.

GIS-Based Study of Dental Accessibility and Caries in 3-Year-Old Japanese Children.

OBJECTIVE: This study aimed to reveal the geographic accessibility of dental clinics for most municipalities in Japan in 2015 and to explore the association between dental accessibility and dental caries status in 3-year-old children. METHODS: We computed the accessibility index and accessibility index rate for the population outside a 1-km radius of dental clinics using a geographic information system. We also used spatial autocorrelation analysis (Moran's I statistic) to examine the spatial clustering patterns of dental accessibility in Japanese municipalities. In addition, we adjusted the prevalence of dental caries for most municipalities using empirical Bayesian estimation. Finally, we applied multiple linear regression to scrutinise the associations between dental caries status, including the prevalence of dental caries and decayed and filled teeth (dft), and dental accessibility, with adjustments made for other sociodemographic variables. RESULTS: The distribution of dental accessibility in Japanese municipalities is relatively unequal. Dental accessibility is decent in the 3 metropolitan areas around Tokyo, Osaka, and Nagoya but poor in the Tohoku and Kyushu regions. In addition, dental accessibility is significantly related to the prevalence of dental caries and dft after adjusting for other sociodemographic variables (P < .005). CONCLUSIONS: This study suggests that dental accessibility is considerably connected to the dental caries status of 3-year-old children after excluding financial burden. Preschool children in areas with poor dental accessibility are likely to have poor dental caries status. We also verified the inequality of dental accessibility amongst Japanese municipalities. For the future development of primary oral health care, more attention should be paid to people with a disadvantage in terms of dental accessibility.