Department of Global Health Promotion, Tokyo Medical and Dental University, Bunkyo-ku, Japan.
Department of Oral Health Promotion, Tokyo Medical and Dental University, Bunkyo-ku, Japan.
Community Dent Oral Epidemiol. 2023 Dec;51(6):1141-1149. doi: 10.1111/cdoe.12847. Epub 2023 Feb 13.
Water fluoridation is an effective measure to prevent dental caries. In Japan, artificial water fluoridation is not implemented, and tap water natural fluoride concentration geographically differs because of various soil natures. This study aimed to examine the association between tap water natural fluoride and parent-reported experience of dental caries in children.
Data from the Longitudinal Survey of Newborns in the twenty-first century, a national birth cohort study following all infants born between January 10-17 and July 10-17, 2001, were analysed. Caregivers answered the child's caries treatment history, a proxy for dental caries, yearly from 5.5 to 12 years of age (N = 202 517 observations from 34 998 children). The annual data on tap water natural fluoride concentration in the municipality of residence were obtained from the national statistics. Cross-classified multilevel Poisson regression models were fitted, adjusting for child, household and municipality characteristics, including average income and dental clinic density.
The average tap water natural fluoride concentration across municipalities was 0.0887 ppm (SD = 0.0422). The proportion of parent-reported experience of child dental caries treatment ranged from 24.9% (at 12 years) to 40.3% (at 7 years) and was lower among children living in municipalities with high natural fluoride concentrations, which were 35.0%, 35.4%, 33.4% and 32.3% for <0.10, 0.10-0.19, 0.20-0.29 and ≥0.30 ppm respectively. A 0.1 ppm increment in tap water natural fluoride after controlling for all covariates was significantly associated with a lower prevalence of parent-reported child dental caries treatment by 3.3% (prevalence ratio = 0.967, 95% credible interval: 0.939, 0.996).
Natural fluoride in tap water showed a protective effect for the parent-reported experience of child dental caries in Japan.
水氟化是预防龋齿的有效措施。在日本，没有实施人工水氟化，由于土壤性质的不同，自来水中天然氟化物的浓度在地理上存在差异。本研究旨在探讨自来水中天然氟化物与父母报告的儿童龋齿经历之间的关系。
本研究使用了 21 世纪新世纪纵向新生儿调查的数据，该研究是一项全国性的出生队列研究，对 2001 年 1 月 10 日至 17 日和 7 月 10 日至 17 日之间出生的所有婴儿进行了跟踪。看护人每年从 5.5 岁到 12 岁（来自 34998 名儿童的 202517 次观察）回答孩子的龋齿治疗史，这是龋齿的一个替代指标。从全国统计数据中获得了居住地自来水中天然氟化物浓度的年度数据。采用交叉分类多水平泊松回归模型进行拟合，调整了儿童、家庭和市町村的特征，包括平均收入和牙科诊所密度。
市町村自来水中天然氟化物的平均浓度为 0.0887ppm（标准差=0.0422）。父母报告儿童接受龋齿治疗的比例从 24.9%（12 岁）到 40.3%（7 岁）不等，且生活在高天然氟化物浓度的市町村的儿童比例较低，分别为<0.10、0.10-0.19、0.20-0.29 和 ≥0.30ppm 的市町村的比例分别为 35.0%、35.4%、33.4%和 32.3%。在控制了所有协变量后，自来水中天然氟化物增加 0.1ppm 与父母报告的儿童龋齿治疗的患病率降低 3.3%显著相关（患病率比=0.967，95%可信区间：0.939，0.996）。
日本自来水中的天然氟化物对父母报告的儿童龋齿经历具有保护作用。
