Research Studies
Study Tracker
Water Fluoridation Risks or Benefits: Summary of the Symposium Presented During the Enamel 11 Meeting Held in Paris France.Abstract
Original abstract online at
https://link.springer.com/article/10.1007/s00223-026-01525-7
Fluoride is widely used in dentistry to prevent dental caries. Fluoride can be naturally present in ground waters, and as a public health measure, many countries have added fluoride to drinking water. Experimental studies show that fluoride can affect the cells of the developing tooth organ to result in dental fluorosis, and cellular effects of fluoride raise concerns about potential neurodevelopmental and endocrine effects. Evidence of increasing levels of fluorosis in populations, have led regulatory organizations to revise their recommendations for optimal doses. To review the scientific evidence related to community water fluoridation and to stimulate discussion among the enamel research community, the organizers of the Enamel 11 meeting invited four speakers with expertise focused on fluoride use in caries prevention (Bruce Dye), fluoride physiology and mechanisms of action (Marília Afonso Rabelo Buzalaf), fluoride effects on human neurodevelopment (Bruce Lanphear), and fluoride related effects on endocrine systems (Jean-Baptiste Fini). An introduction to this symposium is included to provide context, and is followed by a summary of the presentations, which can be viewed at https://youtu.be/vNo2xQYeK9I. The discussion summarizes the comments of the presenters in response to questions by attendees.
References
-
Arnold FA Jr., Dean HT, Knutson JW (1953) Effect of fluoridated public water supplies on dental caries prevalence. Public Health Rep 68:141–148
-
Dean HT (2006) Endemic fluorosis and its relation to dental caries. 1938. Public Health Rep. 121(Suppl 1):213–219. (discussion 212)
-
Marinho VC (2009) Cochrane reviews of randomized trials of fluoride therapies for preventing dental caries. Eur Arch Paediatr Dent 10:183–191. https://doi.org/10.1007/BF03262681
-
Zhang J, Sardana D, Li KY, Leung KCM, Lo ECM (2020) Topical fluoride to prevent root caries: systematic review with network meta-analysis. J Dent Res 99:506–513. https://doi.org/10.1177/0022034520906384
-
Yeung CA (2008) A systematic review of the efficacy and safety of fluoridation. Evid Based Dent 9:39–43. https://doi.org/10.1038/sj.ebd.6400578
-
Bawden JW, Deaton TG, Crenshaw MA (1982) Role of the enamel organ in limiting fluoride uptake during the maturation phase of enamel development. J Dent Res 61:506–509. https://doi.org/10.1177/00220345820610031401
-
Featherstone JD (2000) The science and practice of caries prevention. J Am Dent Assoc 131:887–899. https://doi.org/10.14219/jada.archive.2000.0307
-
ten Cate JM, Buzalaf MAR (2019) Fluoride mode of action: once there was an observant dentist. J Dent Res 98:725–730. https://doi.org/10.1177/0022034519831604
-
Adamek E, Paw?owska-Góral K, Bober K (2005) In vitro and in vivo effects of fluoride ions on enzyme activity. Ann Acad Med Stetin 51:69–85
-
Suzuki M, Ikeda A, Bartlett JD (2018) Sirt1 overexpression suppresses fluoride-induced p53 acetylation to alleviate fluoride toxicity in ameloblasts responsible for enamel formation. Arch Toxicol 92:1283–1293. https://doi.org/10.1007/s00204-017-2135-2
-
Johnston NR, Strobel SA (2020) Principles of fluoride toxicity and the cellular response: a review. Arch Toxicol 94:1051–1069. https://doi.org/10.1007/s00204-020-02687-5
-
Prostak KS, Skobe Z (1996) Anion translocation through the enamel organ. Adv Dent Res 10:238–244. https://doi.org/10.1177/08959374960100022001
-
Buzalaf MAR, Whitford GM (2011) Fluoride metabolism. Monogr Oral Sci 22:20–36. https://doi.org/10.1159/000325107
-
Marquis RE (1995) Antimicrobial actions of fluoride for oral bacteria. Can J Microbiol 41:955–964. https://doi.org/10.1139/m95-133
-
Ji C, Stockbridge RB, Miller C (2014) Bacterial fluoride resistance, fluc channels, and the weak acid accumulation effect. J Gen Physiol 144:257–261. https://doi.org/10.1085/jgp.201411243
-
Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, Farmus L, Ayotte P, Muckle G, Lanphear B (2020) Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environ Int 134:105315. https://doi.org/10.1016/j.envint.2019.105315
-
Green R, Rubenstein J, Popoli R, Capulong R, Till C (2020) Sex-specific neurotoxic effects of early-life exposure to fluoride: a review of the epidemiologic and animal literature. Curr Epidemiol Rep 7:263–273. https://doi.org/10.1007/s40471-020-00246-1
-
Bashash M, Marchand M, Hu H, Till C, Martinez-Mier EA, Sanchez BN, Basu N, Peterson KE, Green R, Schnaas L, Mercado-Garcia A, Hernandez-Avila M, Tellez-Rojo MM (2018) Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6-12years of age in Mexico City. Environ Int 121:658–666. https://doi.org/10.1016/j.envint.2018.09.017
-
Bashash M, Thomas D, Hu H, Martinez-Mier EA, Sanchez BN, Basu N, Peterson KE, Ettinger AS, Wright R, Zhang Z, Liu Y, Schnaas L, Mercado-Garcia A, Tellez-Rojo MM, Hernandez-Avila M (2017) Prenatal fluoride exposure and cognitive outcomes in children at 4 and 6–12 years of age in Mexico. Environ Health Perspect 125:097017. https://doi.org/10.1289/EHP655
-
Barberio AM, Quinonez C, Hosein FS, McLaren L (2017) Fluoride exposure and reported learning disability diagnosis among Canadian children: implications for community water fluoridation. Can J Public Health 108:e229–e239. https://doi.org/10.17269/CJPH.108.5951
-
Taylor KW, Eftim SE, Sibrizzi CA, Blain RB, Magnuson K, Hartman PA, Rooney AA, Bucher JR (2025) Fluoride exposure and children’s IQ scores: a systematic review and meta-analysis. JAMA Pediatr 179:282–292. https://doi.org/10.1001/jamapediatrics.2024.5542
-
Mullenix PJ, Denbesten PK, Schunior A, Kernan WJ (1995) Neurotoxicity of sodium fluoride in rats. Neurotoxicol Teratol 17:169–177. https://doi.org/10.1016/0892-0362(94)00070-t
-
Yamashita S, Okamoto M, Fujiwara N, Achong-Bowe R, Brueckner S, Mendonca M, Kuriki N, Harigaya H, Trevizol JS, Kukhianidze D, Zhong R, Cooley MA, Shindo S, Memida T, Dhillon NG, Yamakoshi Y, Han X, Kawai T, Buzalaf MAR, Everett ET, Suzuki M (2025) Developmental vulnerability to fluoride toxicity: enamel and clearance differences in adolescent versus mature mice. Arch Toxicol. https://doi.org/10.1007/s00204-025-04245-3
-
Jedeon K, Houari S, Loiodice S, Thuy TT, Le Normand M, Berdal A, Babajko S (2016) Chronic exposure to bisphenol A exacerbates dental fluorosis in growing rats. J Bone Min Res 11:1955–1966. https://doi.org/10.1002/jbmr.2879
-
Picard E, De Palma FDE, Loiodice S, Carbonnier V, Achiedo S, Mimoun N, Mutale D, Doublier S, Durand S, Bourgin M, Aprahamian F, Cordier P, Gutter L, Jedeon K, Naud MC, Noirez P, Ricort JM, Slimani L, Kroemer G, Behar-Cohen F, Maiuri MC, Babajko S (2025) Long-term exposure of mice to sodium fluoride and to a mixture of endocrine disruptors causes tooth enamel and retina abnormalities associated with changes in hepatic metabolism. Environ Int 205:109861. https://doi.org/10.1016/j.envint.2025.109861
-
Leite GA, Sawan RM, Teófilo JM, Porto IM, Sousa FB, Gerlach RF (2011) Exposure to lead exacerbates dental fluorosis. Arch Oral Biol 56:695–702. https://doi.org/10.1016/j.archoralbio.2010.12.011
-
Beltrán-Aguilar ED, Barker L, Dye BA (2010) Prevalence and severity of dental fluorosis in the United States, 1999–2004. NCHS Data Brief. 1–8. https://www.cdc.gov/nchs/data/databriefs/db53.pdf
-
Ge QD, Tan Y, Luo Y, Wang WJ, Zhang H, Xie C (2018) MiR-132, miR-204 and BDNF-TrkB signaling pathway may be involved in spatial learning and memory impairment of the offspring rats caused by fluorine and aluminum exposure during the embryonic stage and into adulthood. Environ Toxicol Pharmacol 63:60–68. https://doi.org/10.1016/j.etap.2018.08.011
-
Peña LCS, Hernández AB, Del Razo LM (2024) Decreased arsenic disposition and alteration of its metabolic profile in mice coexposed to fluoride. Biol Trace Elem Res 202:1594–1602. https://doi.org/10.1007/s12011-023-03764-3
-
DenBesten PK, Zhu L, Li W, Tanimoto K, Liu H, Witkowska HE (2011) Fluoride incorporation into apatite crystals delays amelogenin hydrolysis. Eur J Oral Sci 119 Suppl 1:3–7. https://doi.org/10.1111/j.1600-0722.2011.00903.x
-
Denbesten P, Li W (2011) Chronic fluoride toxicity: dental fluorosis. Monogr Oral Sci 22:81–96. https://doi.org/10.1159/000327028
-
Houari S, Wurtz T, Ferbus D, Chateau D, Dessombz A, Berdal A, Babajko S (2014) Asporin and the mineralization process in fluoride-treated rats. J Bone Min Res 29:1446–1455. https://doi.org/10.1002/jbmr.2153
-
Lacruz RS, Habelitz S, Wright JT, Paine ML (2017) Dental enamel formation and implications for oral health and disease. Physiol Rev 97:939–993. https://doi.org/10.1152/physrev.00030.2016
-
Houari S, Picard E, Wurtz T, Vennat E, Roubier N, Wu TD, Guerquin-Kern JL, Duttine M, Thuy TT, Berdal A, Babajko S (2019) Disrupted iron storage in dental fluorosis. J Dent Res 98:994–1001. https://doi.org/10.1177/0022034519855650
-
Dean HT, McKay FS, Elvove E, United States. Public Health Service (1938) Mottled enamel survey of Bauxite, Ark., ten years after a change in the common water supply. U. S. Govt. print. off., Washington
-
Cheryl A, Dieter MA, Maupin, Rodney R, Caldwell MA, Harris, Tamara I, Ivahnenko JK, Lovelace NL, Barber, Kristin S, Linsey (2015) Estimated use of water in the United States in 2015. https://doi.org/10.3133/cir1441
-
National Toxicology Program (2024) NTP Monograph on the state of the science concerning fluoride exposure and neurodevelopment and cognition: a systematic review. Reearch Triangle Park, NC: National Toxicology Program. NTP Monograph 08. https://doi.org/10.22427/NTP-MGRAPH-8
-
European Food Safety Authority (EFSA) (2013) Scientific opinion on dietary reference values for fluoride. EFSA J 11:3332. https://doi.org/10.2903/j.efsa.2013.3332
-
McLaren L, Patterson SK, Faris P, Chen G, Thawer S, Figueiredo R, Weijs C, McNeil D, Waye A, Potestio M (2022) Fluoridation cessation and children’s dental caries: a 7-year follow-up evaluation of Grade 2 schoolchildren in Calgary and Edmonton, Canada. Community Dent Oral Epidemiol 50:391–403. https://doi.org/10.1111/cdoe.12685
-
Kessler B, Smith SD (2025) Removing fluoride from water? An oral health crisis unfolds. JAMA Health Forum 6:e253296–e253296. https://doi.org/10.1001/jamahealthforum
-
Buzalaf MAR (2018) Review of fluoride intake and appropriateness of current guidelines. Adv Dent Res 29:157–166. https://doi.org/10.1177/0022034517750850
-
Pereira H, Dionizio AS, Araujo TT, Fernandes MDS, Iano FG, Buzalaf MAR (2018) Proposed mechanism for understanding the dose- and time-dependency of the effects of fluoride in the liver. Toxicol Appl Pharmacol 358:68–75. https://doi.org/10.1016/j.taap.2018.09.010
-
Miranda GHN, Alvarenga MOP, Ferreira MKM, Puty B, Bittencourt LO, Fagundes NCF, Pessan JP, Buzalaf MAR, Lima RR (2021) A systematic review and meta-analysis of the association between fluoride exposure and neurological disorders. Sci Rep 11:22659. https://doi.org/10.1038/s41598-021-99688-w
-
Lobo JG, Leite AL, Pereira HA, Fernandes MS, Peres-Buzalaf C, Sumida DH, Rigalli A, Buzalaf MA (2015) Low-level fluoride exposure increases insulin sensitivity in experimental diabetes. J Dent Res 94:990–997. https://doi.org/10.1177/0022034515581186
-
Trevizol JS, Buzalaf NR, Dionizio A, Delgado AQ, Cestari TM, Bosqueiro JR, Magalhães AC, Buzalaf MAR (2020) Effects of low-level fluoride exposure on glucose homeostasis in female NOD mice. Chemosphere 254:126602. https://doi.org/10.1016/j.chemosphere.2020.126602
-
(U.S.) National Research Council (NRC), Water CoFiD (2006) Fluoride in Drinking Water: A Scientific Review of EPA’s Standards. National Academies, Washington, DC. https://doi.org/10.17226/11571
-
National Toxicology Program (NTP) (2016) Systematic literature review on the effects of fluoride on learning and memory in animal studies. NTP Research Report 1. Research Triangle Park, NC: National Toxicology Program. https://ntp.niehs.nih.gov/sites/default/files/ntp/results/pubs/rr/reports/rr01_508.pdf
-
Green R, Lanphear B, Hornung R, Flora D, Martinez-Mier EA, Neufeld R, Ayotte P, Muckle G, Till C (2019) Association between maternal fluoride exposure during pregnancy and IQ scores in offspring in Canada. JAMA Pediatr 173:940–948. https://doi.org/10.1001/jamapediatrics.2019.1729
-
Iheozor-Ejiofor Z, Walsh T, Lewis SR, Riley P, Boyers D, Clarkson JE, Worthington HV, Glenny AM, O’Malley L (2024) Water fluoridation for the prevention of dental caries. Cochrane Database Syst Rev 10:CD010856. https://doi.org/10.1002/14651858.CD010856.pub3
-
Guth S, Hüser S, Roth A, Degen G, Diel P, Edlund K, Eisenbrand G, Engel K-H, Epe B, Grune T, Heinz V, Henle T, Humpf H-U, Jäger H, Joost H-G, Kulling SE, Lampen A, Mally A, Marchan R, Marko D, Mühle E, Nitsche MA, Röhrdanz E, Stadler R, van Thriel C, Vieths S, Vogel RF, Wascher E, Watzl C, Nöthlings U, Hengstler JG (2020) Toxicity of fluoride: critical evaluation of evidence for human developmental neurotoxicity in epidemiological studies, animal experiments and in vitro analyses. Arch Toxicol 94:1375–1415. https://doi.org/10.1007/s00204-020-02725-2
-
Do LG, Ha DH, Spencer AJ, Rugg-Gunn A (2025) Controversies and public health implications of community water fluoridation. J Dent Res 220345251394295. https://doi.org/10.1177/00220345251394295
-
Veneri F, Vinceti M, Generali L, Giannone ME, Mazzoleni E, Birnbaum LS, Consolo U, Filippini T (2023) Fluoride exposure and cognitive neurodevelopment: systematic review and dose-response meta-analysis. Environ Res 221:115239. https://doi.org/10.1016/j.envres.2023.115239
-
Committee ES, Bennekou SH, Allende A, Bearth A, Casacuberta J, Castle L, Coja T, Crépet A, Hoogenboom R, Knutsen H, Lambré C, Nielsen SS, Turck D, Civera AV, Villa R, Zorn H, Castenmiller J, Cheyns K, Darney K, Gilbert M, Leblanc J-C, Meyer H, Ntzani E, Paparella M, Vinceti M, Wallace H, Anastassiadou M, Bastaki M, Cattaneo I, Greco L, Lanzoni A, Riolo F, Mosbach-Schulz O, Terron A, Halldorsson T (2025) Updated consumer risk assessment of fluoride in food and drinking water including the contribution from other sources of oral exposure. EFSA J 23:e9478. https://doi.org/10.2903/j.efsa.2025.p230701
-
Goodman CV, Hall M, Green R, Chevrier J, Ayotte P, Martinez-Mier EA, McGuckin T, Krzeczkowski J, Flora D, Hornung R, Lanphear B, Till C (2022) Iodine status modifies the association between fluoride exposure in pregnancy and preschool boys’ intelligence. Nutrients 14:2920. https://doi.org/10.3390/nu14142920
-
Critical Catalyst (2024) France intends to classify sodium fluoride as an endocrine disruptor for human health and reprotoxic. Accessed from: https://criticalcatalyst.com/france-intends-to-classify-sodium-fluoride-as-an-endocrine-disruptor-for-human-health-and-reprotoxic/
-
Bernabe E, Marcenes W, Abdulkader RS, Abreu LG, Afzal S, Alhalaiqa FN, Al-Maweri S, Alsharif U, Anyasodor AE, Arora A, Asgary S, Ashraf T, Balasubramanian M, Banakar M, Barrow A, Bashiri A, Belay SA, Belgaumi UI, Berhie AY, Bhardwaj P, Bhaskar S, Bijani A, Bouaoud S, Cao Y, Chaurasia A, Chen MX, Chu D-T, Cruz-Martins N, Dadras O, Dai X, Diaz D, Du M, Ekholuenetale M, Ekundayo TC, El Tantawi M, Elhadi M, Fagbamigbe AF, Farshidfar N, Fatehizadeh A, Fischer F, Folayan MO, Gaewkhiew P, Gajdács M, Golechha M, Gupta B, Gupta S, Hagins H, Halboub ES, Hamidi S, Hariyani N, Hay SI, Heidari M, Herrera-Serna BY, Heyi DZ, Hostiuc S, Humphrey KM, Ibitoye SE, Ilic MD, Isola G, Kandaswamy E, Kantar RS, Kaur N, Kemmer L, Khader YS, Khateri S, Kisa A, Krishan K, Kruger E, Lalloo R, Li A, Lim SS, Mestrovic T, Mokdad AH, Moreira RS, Morrison SD, Murray CJL, Natto ZS, Nayak BP, Nguyen T, Nguyen VT, Omotayo AO, Padron-Monedero A, Patel J, Patil S, Pawar S, Petcu I-R, Qattea I, Rahman M, Ratan ZA, Riad A, S, Sabour MSNC, Saheb Sharif-Askari S, Sahebkar F, Sakshaug A, Samy JW, Sarode AM, Sawhney SC, Schwendicke M F, et al (2025) Trends in the global, regional, and national burden of oral conditions from 1990 to 2021: a systematic analysis for the Global Burden of Disease Study 2021. Lancet 405:897–910. https://doi.org/10.1016/S0140-6736(24)02811-3
-
Saad H, Escoube R, Babajko S, Houari S (2022) Fluoride intake through dental care products: a systematic review. Front Oral Health 3:916372. https://doi.org/10.3389/froh.2022.916372
Acknowledgements
We thank Dr Bruce Lanphear (Simon Fraser University, Vancouver, Canada) and Dr Bruce Dye (University of Colorado School of Dental Medicine, USA), for their valuable contributions to the webinar.
Ethics declarations
Conflict of interest
Authors disclose no other financial nor non-financial interests that are directly related to the work submitted for publication.
Ethical approval
SB (employee of INSERM) and JBF (employee of MNHN) provide expertise for the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) which is not responsible of the content of the manuscript.
