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Community water fluoridation (CWF) is the adjustment of the natural fluoride concentration of a community water supply to the recommended level for optimal oral health [1]. Fluoridation is a public health measure against tooth decay that benefits people irrespective of age, gender, income, ethnicity, employment or access to treatment. CWF has long been a controversial topic with a lot of misinformation and ‘junk science’ shared through the media, on the internet and now also through social media. Caution should therefore be exercised in evaluating material in this area.
In an area with CWF, health authorities add fluoride to the water supply so that everyone in the community has the opportunity to benefit. CWF is unlike other preventive measures, as no further individual and/or professional efforts are needed to obtain benefit. The fluoridated water is odorless, colorless and tasteless. About 377.7 million people in some 25 countries enjoy the health and economic benefits of fluoride due to adjusted CWF. The optimal fluoride level is considered to be 0.7 ppm F, but needs to be adjusted for local climate and consumption habits [1].
CWF prevents tooth decay by at least 25% or more [2,3], depending on the use of other fluorides such as toothpaste and professionally applied fluoride. In communities benefiting from CWF there are more people who are cavity-free, and for people who have cavities, they are much smaller. Many of the studies were conducted prior to the widespread introduction of fluoride toothpaste.
In over 70 years of CWF there have been no proven adverse health effects. There is an increased risk of mild dental fluorosis (white striations or spots, usually not noticeable except by a dental professional) in CWF areas [2]. Dental fluorosis may also be an aesthetic concern in communities with very high natural levels of fluoride in the drinking water. These communities may look to reduce the fluoride levels in their water.
CWF is the most cost-effective preventive measure against tooth decay. The costs per head of CWF intervention can be very small and for every $1 spent for CWF there may be a $12-$135 benefit.
In communities where CWF is feasible and permitted, it has shown to be the most cost effective, safe and practical public health measure for preventing tooth decay, with excellent health and economic benefits.
Key Further Reading
1- Understanding Optimum Fluoride Intake from Population-Level Evidence.
Spencer AJ, Do LG, Mueller U, Baines J, Foley M, Peres MA. Understanding Optimum Fluoride Intake from Population-Level Evidence. Adv Dent Res. 2018 Mar;29(2):144-156.
2- Water fluoridation for the prevention of dental caries.
Iheozor-Ejiofor Z, Worthington HV, Walsh T, O’Malley L, Clarkson JE, Macey R, Alam R, Tugwell P, Welch V, Glenny AM. Water fluoridation for the prevention of dental caries. Cochrane Database Syst Rev. 2015 Jun 18;(6):CD010856.
Rugg-Gunn AJ, Spencer AJ, Whelton HP, Jones C, Beal JF, Castle P, Cooney PV, Johnson J, Kelly MP, Lennon MA9, McGinley J, O’Mullane D, Sgan-Cohen HD, Sharma PP, Thomson WM, Woodward SM, Zusman SP. Critique of the review of ‘Water fluoridation for the prevention of dental caries’ published by the Cochrane Collaboration in 2015. Br Dent J. 2016 Apr;220(7):335-40.