Projected Outcomes of Removing Fluoride From US Public Water Systems.

Importance: Fluoridation of public water systems has been a cornerstone of public health efforts in the US but has come under increasing scrutiny due to concerns of neurotoxicity.

Objective: To determine the cost-effectiveness of cessation of public water fluoridation and associations with oral health outcomes among US children.

Design, setting, and participants: A cost-effectiveness analysis was conducted to estimate changes in total tooth decay, quality-adjusted life-years (QALYs), and costs associated with removal of fluoride in public water system during 5- and 10-year periods. A microsimulation model of oral health outcomes was constructed based on oral health and water fluoridation data of US children from age 0 to 19 years in a nationally representative sample from the US National Health and Nutrition Examination Survey (NHANES), 2013 to 2016. Sensitivity analyses were conducted to assess the robustness of the simulation results to variation in model input parameters. Data analysis was conducted from November 15, 2024, to February 3, 2025.

Exposure: Cessation of public water fluoridation in the US.

Main outcomes: Changes in dental caries prevalence; total number of decayed teeth and dental fluorosis; QALYs; and costs.

Results: The simulation model was informed by NHANES data of 8484 participants (mean [SD] age, 9.6 (0.1) years; 4188 [weighted percentage, 49.0%] female). In the base-case scenario of eliminating fluoridation, dental caries prevalence and total number of decayed teeth were estimated to increase by 7.5 (95% uncertainty interval [UI], 6.3 to 8.5) percentage points and by 25.4 million (95% UI, 23.3-27.6 million) cases, with a loss of 2.9 million (95% UI, -3.2 to -2.6 million) QALYs at a cost of $9.8 billion (95% UI, $8.7 to $10.8 billion) over 5 years. Sensitivity analyses estimating less efficacy from fluoridation found lower but still substantial harms. Estimates increased for a 10-year horizon compared to a 5-year horizon. Increased tooth decay would disproportionately affect publicly insured and uninsured children compared to those with private dental insurance.

Conclusions and relevance: This cost-effectiveness analysis found that cessation of public water fluoridation would increase tooth decay and health system costs in the US. Despite concerns regarding toxic effects associated with high levels of fluoride, this model demonstrates the substantial ongoing benefits of water fluoridation at safe levels currently recommended by the US Environmental Protection Agency, the National Toxicity Program, and the Centers for Disease Control and Prevention.