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Importance: Previous meta-analyses suggest that fluoride exposure is adversely associated with children’s IQ scores. An individual’s total fluoride exposure comes primarily from fluoride in drinking water, food, and beverages.

Objective: To perform a systematic review and meta-analysis of epidemiological studies investigating children’s IQ scores and prenatal or postnatal fluoride exposure.

Data sources: BIOSIS, Embase, PsycInfo, PubMed, Scopus, Web of Science, CNKI, and Wanfang, searched through October 2023.

Study selection: Studies reporting children’s IQ scores, fluoride exposure, and effect sizes.

Data extraction and synthesis: Data were extracted into the Health Assessment Workplace Collaborative system. Study quality was evaluated using the OHAT risk-of-bias tool. Pooled standardized mean differences (SMDs) and regression coefficients were estimated with random-effects models.

Main outcomes and measures: Children’s IQ scores.

Results: Of 74 studies included (64 cross-sectional and 10 cohort studies), most were conducted in China (n = 45); other locations included Canada (n = 3), Denmark (n = 1), India (n = 12), Iran (n = 4), Mexico (n = 4), New Zealand (n = 1), Pakistan (n = 2), Spain (n = 1), and Taiwan (n = 1). Fifty-two studies were rated high risk of bias and 22 were rated low risk of bias. Sixty-four studies reported inverse associations between fluoride exposure measures and children’s IQ. Analysis of 59 studies with group-level measures of fluoride in drinking water, dental fluorosis, or other measures of fluoride exposure (47 high risk of bias, 12 low risk of bias; n = 20 932 children) showed an inverse association between fluoride exposure and IQ (pooled SMD, -0.45; 95% CI, -0.57 to -0.33; P < .001). In 31 studies reporting fluoride measured in drinking water, a dose-response association was found between exposed and reference groups (SMD, -0.15; 95% CI, -0.20 to -0.11; P < .001), and associations remained inverse when exposed groups were restricted to less than 4 mg/L and less than 2 mg/L; however, the association was null at less than 1.5 mg/L. In analyses restricted to low risk-of-bias studies, the association remained inverse when exposure was restricted to less than 4 mg/L, less than 2 mg/L, and less than 1.5 mg/L fluoride in drinking water. In 20 studies reporting fluoride measured in urine, there was an inverse dose-response association (SMD, -0.15; 95% CI, -0.23 to -0.07; P < .001). Associations remained inverse when exposed groups were restricted to less than 4 mg/L, less than 2 mg/L, and less than 1.5 mg/L fluoride in urine; the associations held in analyses restricted to the low risk-of-bias studies. Analysis of 13 studies with individual-level measures found an IQ score decrease of 1.63 points (95% CI, -2.33 to -0.93; P < .001) per 1-mg/L increase in urinary fluoride. Among low risk-of-bias studies, there was an IQ score decrease of 1.14 points (95% CI, -1.68 to -0.61; P < .001). Associations remained inverse when stratified by risk of bias, sex, age, outcome assessment type, country, exposure timing, and exposure matrix.

Conclusions and relevance: This systematic review and meta-analysis found inverse associations and a dose-response association between fluoride measurements in urine and […]

For over 70 years, the addition of fluoride to public water as community water fluoridation (CWF or fluoridation) with intent to prevent dental caries continues to be controversial, and risks are seldom included in monetary evaluations. Published operational costs and benefits of fluoridation are used, whereas published and clinical experience treating dental fluorosis are utilized to estimate treatment costs of patient‐perceived dental fluorosis and lost wages from lower IQ (intelligence quotient). Published estimated caries averted, less operational costs at $8 PPPY (per person per year) were used, compensation for functional and cosmetic dental fluorosis $126 PPPY, and lower earnings from presumed harm of developmental neurotoxicity estimated at $438 PPPY. Net loss from CWF is estimated at $556 PPPY, although some individuals will have significantly more or less loss. Previous economic evaluations of fluoridation have estimated caries averted and costs of operations; however, few evaluations include the costs of treating harm. Fluoridation is not cost‐effective if the cost of harm is included. Alternatives for the prevention of dental caries should be promoted, and the cessation of fluoridation is indicated.

Mercury toxicity from amalgam dental fillings and their potential for creating problems in the environment and for human health have prompted the development of new restorative materials. The leading alternatives among these are glass ionomer cements. According to current understanding, restorative materials that slowly release fluoride exert a local cariostatic effect. For this purpose, glass ionomer cements have desirable properties in that they help prevent recurrence of caries by releasing fluoride over a long period. Thus, they function in accord with the major cariostatic mechanism of fluoride, which is believed to be its action to promote remineralization and to influence the morphology of teeth by reducing enamel solubility and by suppressing oral cariogenic bacteria. Although the minimum local concentration of fluoride release required to inhibit demineralization has not been determined, it is reported that the cariostatic ability of fluoride releasing restorative materials is significant. Zirconomer defines a new class of restorative that promises the strength and durability of amalgam with the protective benefits of glass ionomer while completely eliminating the hazards of mercury. The inclusion of specially micronized zirconia fillers in the glass component of zirconomer reinforces the structural integrity of the restoration and imparts superior mechanical properties for the restoration of load-bearing permanent teeth. Combination of outstanding strength, durability, and sustained fluoride protection deems it ideal for multiple applications. The aim of the present study was to determine the fluoride release from glass ionomer cements and compare it with new material zirconomer.