A Fluoride Conversation:What Does the Evidence Say?

A short discussion on the recent fluoride debate

Introduction

“Is fluoride safe for my child”?

 “If I refuse fluoride, will that cause more cavities for my child?”

“Why do I find so many different opinions on fluoride?”

These are some of the genuine questions parents ask.

Every parent desires the best for their child. But in this age of information overload, healthcare decisions can feel daunting and overwhelming.

This article brings together all that you need to know about fluoride — history and scientific background to the current debates and alternatives. A well-informed decision is a more reassuring one.

What Is Fluoride?

Fluoride is widely present in nature. It is found in volcanic rocks, water sources that pass through these rocks, in soil, and in food grown in fluoride rich soil. These natural fluoride belts exist in different parts of the world.

Around 75 years ago, fluoride was added to community drinking water and to commercial products such as dental products, pesticides, food, medicines.¹

How Did Fluoride Become Important in Cavity Prevention?

In the 1900s, McKay and Dr G.V. Black observed strange brown stains on the teeth of children living in Colorado and called it the “Colorado brown stain”. Dr Black later named this as “mottled enamel”. One of the interesting finding about these stains were that these children were also cavity free.^2,3

When similar stains were reported in other areas of the U.S,chemist H.V Churchill analyzed local water sources and found high fluoride levels in those regions.³

In the 1930s, Dr Dean did extensive research on water sources and dental fluorosis (mottled enamel). His goal was to find a safe fluoride level that would prevent cavities without the brown staining.

This led to the first community water fluoridation in Grand Rapids, Michigan, in 1945. A study conducted 15 years later showed that children there had 60 percent less cavities than in a nearby area without water fluoridation.³

What Causes Cavities?

To understand how fluoride works, it helps to first understand how cavities form.

Dental caries or cavities is a preventable disease with many causes. Some of them are:

• High-sugar, high-carbohydrate diets
• Bacteria and saliva in the mouth
• Inadequate oral hygiene
• Mouth breathing

Teeth have three layers:

• The outermost layer, called the enamel
• The second layer, called the dentine
• The third layer, called the pulp or nerve

Dental pain increases as the cavity deepens and approaches the pulp.

The outer enamel layer is made up of hydroxyapatite, a mineral made of calcium and phosphorus.

An imbalance between “demineralization” of the enamel and its “remineralization” causes cavities. In other words, cavities form when the enamel loses minerals faster than it can rebuild them.

Here is how that works: when sugary foods stick to the enamel bacteria feed on them and break them down into acids. This lowers the pH in the mouth, which causes minerals to move out of the teeth to the saliva. When the pH returns to normal, minerals move back from the saliva to the teeth. This is called remineralization.

Cavities start to form and progress when demineralization happens more often than remineralization.⁴

What Does Fluoride Do?

Fluoride works in two ways: systematically and topically.

When fluoride is consumed, it has systemic effects. It becomes part of the forming tooth structure. Topical fluoride is applied directly to the already-formed teeth.

Examples of systemic fluoride include fluoridated water, milk, salt and fluoride supplements. Toothpastes, mouthwashes, gels are used topically.

Fluoride helps to:

• Reduce demineralization-fluoride combines with the hydroxyapatite in enamel making it more acid-resistant.
• Increase remineralization– it stabilizes calcium and phosphorus near the tooth surface.
• Disrupt the bacterial ability to produce acid.⁵

Fluoride was added to community water to strengthen enamel as it forms, especially in children to reduce cavities.

Did Fluoride Work?

The Centre for Disease Control and Prevention (CDC) in 1991, named water fluoridation as one of the top ten great public health achievements in the twentieth century. Because of this evidence, the FDI World Dental Federation, a non-governmental organization representing millions of dentists worldwide supported both systemic and topical use of fluoride.⁶

About 400 million people worldwide drink fluoridated water, with about half of those in the U.S. However, 97 percent of Europe does not have water fluoridation.⁷ Some countries that have not opted for water fluoridation have introduced milk and salt fluoridation.⁶

Key research findings include:

• A US study in 2018 examined over 13,000 children. In every 100 children, there was 130 fewer decayed teeth due to water fluoridation.⁸
• That  same year, Australian research found 86 percent more chances for cavities in preschool children without fluoridation.⁹
• Calgary, Canada stopped  water fluoridation in 2011. A 2021 study found increased cavity rates in children, which led the city council to vote to restore fluoridation.¹⁰

However, only less than 10 percent of world population has water fluoridation due to their naturally present fluoride in water.³

As fluoride became available from more sources, tracking the exact amount used became difficult.

What Is the Debate Around Fluoride About?

Since the 1960s, fluoride in drinking water has been controversial, with a recent surge in this controversy.¹¹ A Cochrane review in 2015 noted that most supporting studies were done before fluoride toothpaste became widely available.

These studies also did not look at other factors that can reduce cavities-such as greater awareness about sugar, dietary changes, improved oral hygiene and preventive measures.¹

As conclusive evidence was lacking for cavity reduction and more studies of fluoride toxicity came around, anti-fluoride movement has become stronger.¹¹

Some notable policy changes include:

• In 2015, the U.S Public Health Service reduced the level of fluoride in community water to 0.7 milligrams per liter from the initial 0.7- 1.2 milligrams / liter .This was done considering other fluoride sources now available.¹²
• In October 2025, the Food and Drug Administration (FDA) issued a warning against fluoride supplements for children under 3 years of age.
• In 2025, water fluoridation was banned in Florida and Utah, with more states expected to follow in 2026. This has sparked discussions about an increase in the Medicaid cost for treating dental disease in children.¹³

Despite these changes, major organizations, including the  American Academy of Pediatric Dentistry(AAPD),AmericanAcademyofPediatrics(AAP),AmericanDentalAssociation (ADA)and other major organizations  maintain that fluoride is an effective and safe method for preventing caries.¹⁴

What Are the Available Alternatives?

The International Academy of Oral Medicine and Toxicology (IAOMT) has published a position paper regarding its anti-fluoride advocacy. Other organizations have also raised concerns,citing growing evidence of more risk and less benefit than previously thought.¹

Functional dentistry takes a more holistic approach to cavities, using methods such as individual saliva pH and bacterial profile testing, dietary changes, remineralization methods  and biologically friendly dental treatments.

Some current alternatives to fluoride include:

• Nano hydroxyapatite
• Silver diamine fluoride
• Calcium phosphate Technology (CPP-APP)
• Calcium fluoride — (considered a safer alternative)
• Xylitol

Though a full review of the research on these options is beyond this article, early findings look promising for cavity prevention and safety.^15–18

However, the body of research supporting them is not yet as large as that on traditional fluoride,and they are yet to be widely accepted as alternatives.

To Conclude

Though there is evidence on both sides, every treatment and preventive plan will be unique to each child. A thorough discussion with the dental provider, one that carefully weighs the evidence-based benefits and risks, is the best way to arrive at a balanced conclusion.

References

1.   Kennedy D, Franklin T, Kall J, Cole G. International Academy of Oral Medicine and Toxicology (IAOMT) Position Paper against Fluoride Use in Water, Dental Materials, and Other Products for Dental and Medical Practitioners, Dental and Medical Students, the General Public, and Policy Makers,2024.

2.   Daws S. Baltimore and the Beginnings of the Fluoride Controversy. J Hist Dent. 2015;63(2):54-63.

3.   Aoun A, Darwiche F, Al Hayek S, Doumit J. The Fluoride Debate: The Pros and Cons of Fluoridation. Prev Nutr Food Sci. 2018;23(3):171-180. doi:10.3746/pnf.2018.23.3.171

4.   Usha C, R S. Dental caries – A complete changeover (Part I). J Conserv Dent JCD. 2009;12(2):46-54. doi:10.4103/0972-0707.55617

5.   Yeh CH, Wang YL, Vo TTT, Lee YC, Lee IT. Fluoride in Dental Caries Prevention and Treatment: Mechanisms, Clinical Evidence, and Public Health Perspectives. Healthcare. 2025;13(17):2246. doi:10.3390/healthcare13172246

6.   Samaranayake L, Porntaveetus T, Tsoi J, Tuygunov N. Facts and Fallacies of the Fluoride Controversy: A Contemporary Perspective. Int Dent J. 2025;75(4):100833. doi:10.1016/j.identj.2025.04.013

7.   Osmunson B, Cole G. Community Water Fluoridation a Cost-Benefit-Risk Consideration. Public Health Chall. 2024;3(4):e70009. doi:10.1002/puh2.70009

8.   Slade GD, Grider WB, Maas WR, Sanders AE. Water Fluoridation and Dental Caries in U.S. Children and Adolescents. J Dent Res. 2018;97(10):1122-1128. doi:10.1177/0022034518774331

9.   McLaren L, Patterson SK, Faris P, et al. 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. 2022;50(5):391-403. doi:10.1111/cdoe.12685

10. McLaren L, Patterson SK, Faris P, et al. 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. 2022;50(5):391-403. doi:10.1111/cdoe.12685

11. Unde MP, Patil RU, Dastoor PP. The Untold Story of Fluoridation: Revisiting the Changing Perspectives. Indian J Occup Environ Med. 2018;22(3):121-127. doi:10.4103/ijoem.IJOEM_124_18

12. U.S. Public Health Service Recommendation for Fluoride Concentration in Drinking Water for the Prevention of Dental Caries. Public Health Rep. 2015;130(4):318-331. doi:10.1177/003335491513000408

13. Sall L. How Ending Water Fluoridation Would Affect Children and State Medicaid Costs – CareQuest Institute. January 29, 2026. Accessed May 30, 2026. https://carequest.org/how-ending-water-fluoridation-would-affect-children-and-state-medicaid-costs/

14. AAPD | AAPD Statement on Recent FDA Announcement Related to Fluoride Supplements. Accessed May 20, 2026. https://www.aapd.org/statement-on-recent-fda-announcement-to-fluoride-supplements/

15. Cocco F, Salerno C, Wierichs RJ, et al. Hydroxyapatite-Fluoride Toothpastes on Caries Activity: A Triple-Blind Randomized Clinical Trial. Int Dent J. 2025;75(2):632-642. doi:10.1016/j.identj.2024.09.037

16. Quritum M, Abdella A, Amer H, El Desouky LM, El Tantawi M. Effectiveness of nanosilver fluoride and silver diamine fluoride in arresting early childhood caries: a randomized controlled clinical trial. BMC Oral Health. 2024;24(1):701. doi:10.1186/s12903-024-04406-3

17. Asadi M, Majidinia S, Bagheri H, Hoseinzadeh M. The Effect of Formulated Dentin Remineralizing Gel Containing Hydroxyapatite, Fluoride, and Bioactive Glass on Dentin Microhardness: An In Vitro Study. Int J Dent. 2024;2024:4788668. doi:10.1155/2024/4788668

18. O’Hagan-Wong K, Enax J, Meyer F, Ganss B. The use of hydroxyapatite toothpaste to prevent dental caries. Odontology. 2022;110(2):223-230. doi:10.1007/s10266-021-00675-4

19. Prince A, Roy S, McDonald D. Exploration of the Antimicrobial Synergy between Selected Natural Substances on Streptococcus mutans to Identify Candidates for the Control of Dental Caries. Microbiol Spectr. 2022;10(3):e0235721. doi:10.1128/spectrum.02357-21