Evidence map›Paper›PMID 40824332›Full record

ArticleBiological trace element research2026

Optimal Fluoride Concentration in Drinking Water for Preventing Dental Fluorosis and Caries in 8-12-Year-Old Children in Qingdao, China: A Restricted Cubic Spline and Spatial Epidemiological Analysis Following Rural Safe Drinking Water Interventions in Endemic Fluorosis Region.

Xiaojuan Dou, Xiaoyi Liu, Shitao Liu, Changxun Ge, Shirui Yan, Di Wu, Xinyue Meng, Xinxiao Li, Junrui Pei, Fengying Ji

Abstract read
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In one paragraph

Article in Biological trace element research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

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PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

10 authors.

Xiaojuan DouQingdao Municipal Center for Disease Control and Prevention, Qingdao, 266000, Shandong Province, China.
Xiaoyi LiuQingdao Municipal Center for Disease Control and Prevention, Qingdao, 266000, Shandong Province, China.
Shitao LiuPingdu City Center for Disease Control and Prevention, Pingdu, 266700, Shandong Province, China.
Changxun GeQingdao Municipal Center for Disease Control and Prevention, Qingdao, 266000, Shandong Province, China.
Shirui YanKey Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province, 150081, China.
Di WuKey Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province, 150081, China.
Xinyue MengDepartment of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
Xinxiao LiKey Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province, 150081, China.
Junrui PeiKey Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, Heilongjiang Province, 150081, China. peijunrui@ems.hrbmu.edu.cn.
Fengying JiQingdao Municipal Center for Disease Control and Prevention, Qingdao, 266000, Shandong Province, China. jfy-5@126.com.

Funding

National Natural Science Foundation of China [82473747];[82273749]
6 · The paper itself

Abstract

Maintaining optimal fluoride levels in drinking water is crucial for balancing dental caries prevention and fluorosis risk in children. This cross-sectional study investigated 12,163 children aged 8-12 years across 934 villages in Qingdao, China, following water safety interventions in an endemic fluorosis regions. Water fluoride concentrations were measured via spectrophotometry, while dental examinations assessed fluorosis (Dean's classification) and caries (DMFT index). Spatial epidemiological mapping, restricted cubic spline (RCS) models, and multivariate logistic regression were integrated to analyze geographic patterns, dose-response relationships, and risk thresholds. Results demonstrated an overall fluorosis prevalence of 3.2% and caries prevalence of 27.0%. RCS analysis revealed a nonlinear positive association between fluoride levels and fluorosis risk (threshold: 0.70 mg/L), alongside a U-shaped caries-fluoride relationship exhibiting minimal caries risk at 0.70-0.73 mg/L. Multivariate regression identified significantly elevated fluorosis odds (adjusted OR = 1.71, 95%CI 1.29 - 2.28) at concentrations > 0.85 mg/L, while 0.70-0.73 mg/L optimally minimized caries. Spatial clustering of high-fluoride regions in northwestern Qingdao correlated with fluorosis hotspots. These findings establish 0.70-0.73 mg/L as the optimal fluoride concentration range for dual caries prevention and fluorosis mitigation in this population. The study advocates for dynamic adjustments to water fluoridation standards and geographically targeted interventions in high-risk regions, offering evidence-based strategies for public health policymaking in fluorosis-endemic regions.

Indexed as

Dental CariesDrinking WaterFluoridesFluorosis, DentalChildChinaCross-Sectional StudiesFemaleHumansMaleRural PopulationDrinking WaterFluoridesDental cariesDental fluorosisDrinking water fluorideRestricted cubic splineSpatial epidemiology

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.