Does cessation of community water fluoridation lead to an increase in tooth decay? A systematic review of published studies

Abstract

BackgroundCessation of community water fluoridation (CWF) appears to be occurring with increasing frequency in some regions. Our objective was to comprehensively review published research on the impact of CWF cessation on dental caries.MethodsWe searched 13 multidisciplinary databases. Results were synthesised qualitatively and quantitatively.ResultsWe identified 15 instances of CWF cessation (‘intervention’) in 13 countries, which covered a broad time frame (1956–2003) and diverse geographical and political/economic contexts. Overall, results were mixed, but pointed more to an increase in caries postcessation than otherwise. For example, of the 9 studies with at least moderate methodological quality based on criteria we developed for this review, 5 showed an increase in caries postcessation. 3 studies did not show an increase in caries postcessation; however, important postcessation changes (eg, implementation of alternative fluoride delivery programmes) and/or large-scale social change may have contributed to those effects. Of the 3 study groupings that permitted quantitative synthesis, 2 showed statistically significant mean overall increase in caries postcessation; however, quantitative synthesis results must be interpreted cautiously.ConclusionsOverall, the published research points more to an increase in dental caries post-CWF cessation than otherwise. However, the literature is highly diverse and variable in methodological quality. To build this literature, it is important to exploit research opportunities presented by CWF cessation. Remaining knowledge gaps include the impact of CWF cessation on the distribution of dental caries (ie, equitable or not) and understanding the decision-making circumstances around CWF cessation.

Fluoridation cessation: More science from Alberta

“…Studies of fluoridation cessation and dental caries are few in number, highly diverse in time and place, and variable in quality 5. Our research improves on limitations of previous studies, and we anticipate that future studies will improve on ours.…”

“…One could study the effects of fluoridation cessation by observing one community over time, as some have performed 5. Our design is strengthened by including a comparison community.…”

Personal oral hygiene and dental caries: A systematic review of randomised controlled trials

“…This dental defect hypothesis was consistent with the epidemiology of dental caries and widely accepted in the medical and dental professions . The dental defect hypothesis ended up explaining dramatic historical and geographical trends in dental caries prevalence in ways that the oral hygiene hypothesis could not . The ubiquity of dental caries in the early 20th century was attributed to sugar, rickets and paediatric fevers, and the latter two identified as causes of dental defects .…”

Methodological considerations for designing a community water fluoridation cessation study

“…Considering socioeconomic variations in caries risk level, it is also important to use an equity lens to assess whether CWF cessation has an impact on oral health disparities in communities. Unfortunately, few cessation studies have been conducted . This may be due to the methodological challenges associated with evaluating population‐based strategies.…”