How the public's knowledge, attitudes, and practice intersect with scientific evidence about fluoride.

For over 75 years, community water fluoridation has been implemented as a public health strategy to reduce dental caries. While early studies suggested dramatic reductions in dental caries, recent evidence indicates that the benefits of community water fluoridation are more modest. Concurrently, concerns have grown over rising rates of enamel fluorosis and possible links between fluoride intake and lowered intelligence in children and thyroid hormone disruption, even at exposure levels found in fluoridated regions. This first part of this paper discusses the historical context and current scientific evidence on the effectiveness of community water fluoridation and safety of systemic fluoride. The second part presents findings from a fluoride survey conducted with 8011 adults in Canada and the U.S. The survey assessed knowledge about fluoride, public perceptions of the risks and benefits of community water fluoridation, and fluoride use with young children. Overall, 60 % of respondents correctly identified why fluoride is added to drinking water. Knowledge of community water fluoridation was higher among older, more educated, and White participants. Among those familiar with community water fluoridation, 51 % expressed support, 27 % opposed it, and 25 % were neutral. Support was primarily driven by confidence in its safety and benefits, while opposition was driven by safety concerns and perceived violations of personal freedom. Trust in public health officials was higher among supporters (87 %) compared with non-supporters of community water fluoridation (52.1 %). When presented with hypothetical risk-benefit scenarios, participants consistently prioritized the prevention of potential health risks, such as reduced IQ, over the relatively modest dental benefit of preventing one cavity. The survey also revealed that most parents report using more fluoride toothpaste for young children than recommended, suggesting a gap in adherence to safe fluoride use guidelines. Our findings highlight mixed public views on community water fluoridation and knowledge gaps surrounding fluoride toothpaste use with children, underscoring the need for clear, evidence-based communication about fluoride exposures.