Learning resources Health professionals Research and evidence Effectiveness of community water fluoridation for reducing tooth decay Community water fluoridation (CWF) means adjusting fluoride levels in public water supplies to help reduce tooth decay across the population. In the United Kingdom, schemes often aim around 1.0 mg/L, with 1.5 mg/L reflecting World Health Organization guideline limits. In the United States, the Centers for Disease Control and Prevention supports a target of 0.7 mg/L. What the evidence shows Children in fluoridated areas usually have less tooth decay. Benefits today are smaller than decades ago, likely due to fluoride toothpaste use. Modern studies show modest reductions, especially in baby teeth. When fluoridation stops, decay levels often rise. Major systematic review & meta-analysis Cochrane Review on Water Fluoridation (2024 update) Putting fluoride into public water may mean children get a less decay in their baby teeth. It may also mean more children grow up without any tooth decay. The improvements seen from water fluoridation today are likely smaller than in the past, because fluoride toothpaste is now widely used. View study on Cochrane Library Water fluoridation systematic review (2000) - University of York Large review of research into water fluoridation. Found more children were free from tooth decay in fluoridated areas. Estimated around a 15% increase in caries-free children. Evidence suggested fluoridation helped reduce dental health inequalities in children. View report (PDF) Major national evidence evaluation National Health and Medical Research Council Evidence Evaluation Report (2016) Found consistent evidence that fluoridation reduces tooth decay. Larger effects were seen in older studies than modern ones. View report (PDF) Other key studies Cumbria natural experiment (“CATFISH”), England (2024) Younger children in fluoridated areas had lower decay rates. Benefits were clearer in baby teeth than permanent teeth. Did not show strong differences in effect by deprivation level. View study in Community Dentistry and Oral Epidemiology Forum on fluoride report, Ireland (2002) National review found water fluoridation at 1ppm improved dental health across the population. No evidence of harm to general health was identified. An increase in dental fluorosis was observed. Recommended continuing fluoridation but reducing the level to 0.7ppm to lower fluorosis risk while keeping benefits. View study (PDF) National preschool study, New Zealand (2020) Children in non-fluoridated areas had higher odds of severe decay. Covered almost the whole national preschool population (275,843 children). View study in JAMA Pediatrics Lifetime exposure study, Australia (2015) Lower lifetime exposure linked with substantially more decay. Showed a stepwise pattern across exposure levels. Included both baby and permanent teeth outcomes. View study in the Australian Dental Journal Fluoridation cessation: Calgary vs Edmonton (2021) Higher decay levels seen in the city that stopped fluoridation. Comparison was several years after cessation. Supports findings from other cessation reviews. View study in Community Dentistry and Oral Epidemiology Hospital tooth extraction study, England (2018) Fluoridated areas had much lower hospital admissions for child tooth extractions. Reflects impact on more severe disease outcomes. Based on national routine health data. View study on GOV.UK Manage Cookie Preferences