There is evidence supporting the benefits of fluoride for oral health purposes, which has been shown to reverse the initiation and development of dental caries. However, there remain uncertainties as to whether the mineral is essential for the general population. This is one of the main issues driving conversations about whether the fluoridation of mains water supplies is ethical – or necessary. Even among the dental professional community, discussion continues.
Fluoride sources
The adequate daily intake of fluoride is 0.7mg for toddlers, 3-4mg for adults, female and male respectively.[i] The threshold for anyone over the age of 9 years is 10mg.[ii] A potential consequence of excessive long-term ingestion is dental fluorosis – especially in children while they’re still developing. An accidental overdose of fluoride can also cause nausea, vomiting, abdominal pain, diarrhoea, periostitis and even death in extremely rare cases.i
Fluoride is most typically consumed within food, particularly brewed black tea, coffee, tinned shrimp, raisins, potatoes, rice and cottage cheese.[iii] In addition to dietary options, fluoride intake can be increased via oral supplements, varnish applications, toothpaste and water consumption. Supplements are proven to reduce caries risk,[iv] although they have largely been replaced by topical fluoride varnish applications over time. The latter is effective for caries prevention and reduction, remineralising the teeth for enhanced enamel strength.[v]
Toothpaste is probably the easiest and most common way to access fluoride. As dental professionals, we are tasked with recommending products with the appropriate fluoride content for each of our patients.
Water is the most contentious source of them all. Fluoride only occurs naturally in water in very small concentrations, meaning that most people would be unlikely to gain the associated health benefits.
Forcing the issue
Water fluoridation was initially introduced in the UK in 1955, when schemes were initiated in Watford, Kilmarnock and Anglesey. Analysis of the results found that 5-year-old children in these areas had 50% less caries than those in the control areas. Fluoridation of drinking water also later commenced in Birmingham and various cities in the North East and then North West of England throughout the 1960s and ‘70s.[vi]
Today, water fluoridation is only implemented in a handful of regions, including Newcastle upon Tyne, Workington, Scunthorpe, Lincoln, Birmingham, Bath, Norwich and Cambridge.[vii] Expansion has been hindered by the potential harm that fluoride might cause, the key concern being fluorosis, particularly among children. There have also been questions regarding associations between fluoridated drinking water and adverse systemic effects like bone cancer, Down’s syndrome and kidney issues, though there is not sufficient evidence supporting these at this time.[viii]
The ethical aspect of widespread water fluoridation is another leading cause of opposition. It is also not a new one, having been debated since the ‘90s.[ix] The issue here is the elimination of people’s choice regarding whether they consume fluoridated water or not.
A professional dilemma
Having spoken to colleagues about the matter, there are conflicting thoughts even among us. To avoid causing additional confusion or concern among patients, I feel the key is to promote prevention as a whole. We should be educating patients with the facts and encouraging them to make an informed choice for themselves. Whether they support water supply fluoridation or not, there are likely to be many other ways they can enhance their oral health.
EndoCare, led by Dr Michael Sultan, is one of the UK’s most trusted Specialist Endodontist practices. Through the use of the latest technologies and techniques, the highly-trained team can offer exceptional standards of care – always putting the patient first. What’s more, EndoCare is a dependable referral centre, to which dentists from across the country send their patients for the best in specialist endodontic treatment.
[i] Aoun A, Darwiche F, Al Hayek S, Doumit J. The Fluoride Debate: The Pros and Cons of Fluoridation. Prev Nutr Food Sci. 2018 Sep;23(3):171-180. doi: 10.3746/pnf.2018.23.3.171. Epub 2018 Sep 30. PMID: 30386744; PMCID: PMC6195894.
[ii] Consultants in Dental Public Health Group. Recommendations on the use of fluoride toothpaste and fluoride supplements in Scotland (2022). https://www.scottishdental.nhs.scot/wp-content/uploads/2022/06/CsDPH-Fluoride-Recommendations-2022.pdf [Accessed July 2025]
[iii] National Institutes of Health. Office of Dietary Supplements. Fluoride. Fact sheet for health professionals. https://ods.od.nih.gov/factsheets/Fluoride-HealthProfessional/ [Accessed July 2025]
[iv] Tubert-Jeannin S, Auclair C, Amsallem E, Tramini P, Gerbaud L, Ruffieux C, Schulte AG, Koch MJ, Rège-Walther M, Ismail A. Fluoride supplements (tablets, drops, lozenges or chewing gums) for preventing dental caries in children. Cochrane Database Syst Rev. 2011 Dec 7;2011(12):CD007592. doi: 10.1002/14651858.CD007592.pub2. PMID: 22161414; PMCID: PMC6876544.
[v] Fluoride Varnishes for Dental Health: A Review of the Clinical Effectiveness, Cost-effectiveness and Guidelines [Internet]. Ottawa (ON): Canadian Agency for Drugs and Technologies in Health; 2016 Oct 26. SUMMARY OF EVIDENCE. Available from: https://www.ncbi.nlm.nih.gov/books/NBK401516/
[vi] Goodwin M, Emsley R, Kelly MP, et al. Evaluation of water fluoridation scheme in Cumbria: the CATFISH prospective longitudinal cohort study [Internet]. Southampton (UK): National Institute for Health and Care Research; 2022 Nov. (Public Health Research, No. 10.11.) Chapter 3, History and implementation of water fluoridation as a public health intervention. Available from: https://www.ncbi.nlm.nih.gov/books/NBK586997/
[vii] Office for Health Improvement & Disparities. Department of Health & Social Care. Guidance. Chapter 9: Fluoride. November 2021. https://www.gov.uk/government/publications/delivering-better-oral-health-an-evidence-based-toolkit-for-prevention/chapter-9-fluoride [Accessed July 2025]
[viii] Department of Health & Social Care. Policy Paper. Health and Care Bill: water fluoridation. March 2022. https://www.gov.uk/government/publications/health-and-care-bill-factsheets/health-and-care-bill-water-fluoridation [Accessed July 2025]
[ix] Coggon D, Cooper C. Fluoridation of water supplies. Debate on the ethics must be informed by sound science. BMJ. 1999 Jul 31;319(7205):269-70. doi: 10.1136/bmj.319.7205.269. PMID: 10426716; PMCID: PMC1126914.
