77-13 Fluoride – Dental Caries Associations and “Optimal” Fluoride – Data Science Approaches to Policy and Decision-Making on Fluoridation

Session: Groundwater and Sustainability: Integrating Science, Technology, and Policy

Presenting Author:

Authors:

Abstract:

Groundwater is a major source of human exposure, through drinking water, to fluoride. The demonstrated reduction in dental caries (DC) by drinking water with “Goldilocks” (not too high or low) fluoride has resulted in widespread artificial fluoridation of drinking water supplies. This has often resulted in controversy between proponents and opponents of fluoridation.

We highlight, with illustrations, and with a focus on the cost-benefit of (de-)fluoridation schemes, some issues for more robust locally-relevant science-, technology- and health-economics- informed policy and decision-making, viz:

(1)    Fluoride~lower DC associations are not 1^st order linear relationships – models that assume such a relationship may substantially underestimate or overestimate the impact of fluoride on (dental) health over particular (especially very low or high) concentration ranges

(2)    Fluoride~lower DC associations may be confounded by other drinking water constituents – this may variably increase or decrease the strength of the association

(3)    Fluoride~lower DC associations may be confounded by socio-economic factors, notably as indicated by poverty/wealth or educational-attainment indices 

(4)    Strong fluoride~lower DC associations observed over 50 years ago may no longer be so relevant because of increased exposure to fluoride from other sources in the present day

(5)    There is no universal “optimal” concentration of fluoride in drinking water

(6)    “Optimal” fluoride concentration without cost-benefit considerations is a flawed concept

(7)    Capex for fluoridation may be largely independent of the increase in drinking water fluoride concentration aspired to and is often much higher than opex even over several years

(8)    De-fluoridation typically largely reduces opex not capex, so has a very different cost-benefit basis from fluoridation proposals

(9)    (De-)fluoridation cost-benefits should be compared with those for (i) other measures to reduce DC; and (ii) measures to address other community priorities

We conclude that decisions on (de-)fluoridation should be nuanced, quantitative, incorporating known confounders, using realistic cost-benefit calculations, including consideration of opportunity costs, and may rationally be very different from one community to another, even before any considerations of community sentiment.

Acknowledgements: MM was funded by a University of Manchester Faculty of Science Deans Doctoral Scholarship Award. We thank Deborah Moore (NHS England) for discussions. The views expressed in the abstract and talk do not necessarily reflect those of any individuals or organisations that we acknowledge here.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-10509

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.