The Cochrane Collaboration Review 2024. This is an update of a Cochrane review first published in 2015, focusing on contemporary evidence about the effects of CWF on dental caries. Reviewed all studies comparing communities that had fluoride added to their water supplies with communities that had no additional fluoride in their water.
Abstract Conclusion: “Studies conducted after 1975 showed that adding fluoride to water may lead to slightly less tooth decay in childrenʼs baby teeth. We could not be sure whether adding fluoride to water reduced tooth decay in childrenʼs permanent teeth or decay on the surfaces of permanent teeth. Adding fluoride to water may slightly increase the number of children who have no tooth decay in either their baby teeth or permanent teeth. However, these results also included the possibility of little or no difference in tooth decay.”.
Large UK Government funded LOTUS study 2024. This study looked at patients aged 12 years and over, attending NHS primary dental care services in England (17.8 million patients). Using recorded residential locations, individuals exposed to drinking water with fluoridated water (≥0.7 mg F/L) were matched to non-exposed individuals using propensity scores. They concluded the same as the CATFISH study, that the very slight difference in decay rates may not be cost-effective in today’s world, particularly for any new supplies where infrastructure costs would also need to be accounted for.
Abstract Conclusion: “Receipt of optimal water fluoridation 2010–2020 resulted in very small positive health effects which may not be meaningful for individuals”.
Large UK Government funded CATFISH study 2022. Major UK Fluoridation Study Finds Much Smaller Benefits And Much Higher Costs Than Prior Claims. This study looked at children under age 12 in two parts of Cumbria. One area with fluoridation (0.9ppm) and the other area without any fluoridation. It found only a very slight difference in tooth decay results leading the authors to conclude that fluoridation may not be cost-effective in today’s world.
Primary Outcomes: For the birth cohort they found a 4% difference For the older school cohort “there was insufficient evidence of an effect” i.e. no difference.
Secondary Outcomes: Found a very small difference of 0.6 decayed, missing or filled teeth for both cohorts. For other outcomes such as dental general anaesthetics (DGAs) “demonstrated no significant differences between the intervention and control groups.”
The Cochrane Collaboration Review 2015. A review of all studies on fluoridation and dental decay. The Cochrane Collaboration is touted as the top independent health science in the world and relied on by New Zealand Ministry of Health to promote fluoridation, finds no modern, reliable evidence that fluoridation reduces dental decay.
Author’s conclusions: “There is very little contemporary evidence, meeting the review’s inclusion criteria, that has evaluated the effectiveness of water fluoridation for the prevention of caries.”
US Government funded Iowa Study looking at the relationship between total daily fluoride intake (from all sources) and several health outcomes of interest, namely: tooth decay, dental fluorosis, and bone health. First report was published in 2009. Finds no relationship between fluoride ingestion and decay rates, but does find strong evidence of fluoride ingestion and dental fluorosis rates.