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Does Fluoridation Prevent Cavities or Cause Tooth Decay?

Updated: Jan 23, 2022

At the end of a stressful day, a bag of candy or a rich chocolate cake is guaranteed to improve your mood. While it is safe to consume some sugary snacks, uncontrolled sugar consumption can result in cavities. Researchers have found fluoride—a mineral that can protect teeth from demineralization caused by acids from oral bacteria and sugar [1]—to be especially useful to prevent cavities. However, like other public health interventions, fluoridation has its limitations.

Oral-B stated (2021) that cavities form when bacteria break down sugars from food and produce acid that demineralizes tooth enamel [2]. The World Health Organization (2019) found that approximately 2.4 billion people suffer from cavities on their permanent teeth and 486 million kids have cavities on their primary teeth [3]. Despite the magnitude of this health concern, the severity of cavities is often unacknowledged, and people see cavities as an unfortunate result of poor oral hygiene and dietary choices. In countries with ample funds and resources (like the United States), many people simply make dental appointments and treat their cavities. However, these treatments come at extremely demanding costs—fillings, crowns, root canals, and extractions cost from hundreds to thousands of dollars.

If treatment for cavities is extremely costly in the United States, it is comparably more difficult and limited for inhabitants of developing countries. Cavities present a serious public health concern in these countries due to lack of funds, healthcare facilities, proper nutritional knowledge, and nutritious foods. This lack of support has resulted in 95% of Filipino 12-year-olds facing “tooth decay or cavities,” and seven in 10 Indian children, 1 in 3 Brazilians, and “one-third of Tanzania teens” having cavities [4].

Since professional dental treatment is not a feasible option for many developing countries, cheaper and more efficient cavity prevention methods, like fluoridation, have been found to have several benefits. Fluoride can be integrated into people’s lives in a variety of ways. A common form of heavy fluoridation is through water fluoridation, but fluoride can also be obtained through toothpaste and mouth rinse [5]. For many countries with enough water, fluoridation has proven to decrease cavities. Dentist, professor, and author C.E. Renson (1986) found decreased cavity rates using water and toothpaste fluoridation in Australia, New Zealand, the United Kingdom, Finland, Nigeria, Thailand, and more countries [6].

Despite the substantial benefits fluoridation provides for cavity prevention, fluoride has also proven to have harmful effects on teeth. When fluoride is consumed in high concentrations (approximately 10 mg 1-1), dental fluorosis can develop [7]. Dental fluorosis is a rather prevalent condition that causes teeth to be stained with yellow-brown color. The World Health Organization investigated some countries that provided water with particularly high fluoride levels—including Canada, China, and Ethiopia—and found that all of them had high rates of fluorosis. Additionally, when fluoride concentration levels are too low (“less than 0.1 mg 1-1”), dental decay can cause further harm to teeth [7].

With fluoride having notable benefits and harms, it is important to consider different factors to determine whether or not fluoride can effectively reduce cavities. The first factor to consider is fluoride concentration. As aforementioned, without proper concentrations, fluoride benefits can be completely lost. A second factor to consider is the population into which fluoride is being integrated. Citizens in lower socioeconomic classes are often targeted with more advertising by sugar industry companies like Coca-Cola, which makes them more prone to developing cavities [4]. Conversely, cavities are not a large issue for those properly equipped to live and eat healthily. Dentists and researchers Lennon et al. stated that “In absence of those sugars in foods and drinks dental caries will not be a public health problem. However where sugar consumption is high or is increasing […] removing fluoride from a local drinking water supply could potentially exacerbate an existing or developing dental public health problem” [8]. Therefore, many factors (such as fluoride concentration and location of fluoridation), are necessary to consider.

To ensure proper water fluoridation to reduce cavities, researchers and public health professionals at the Centers for Disease Control and Prevention have proposed public health interventions. When building a water fluoridation program, the CDC urges that monthly reports regarding fluoridation are made along with updates on fluoride concentrations sent to Public Water Systems and Water Fluoridation Reporting System. The CDC also encourages communities to work with governments to gain funding for inadequate fluoridation systems. Additionally, the CDC states that most fluoridation systems should work towards the Healthy People 2030 goal, which aims for “77.1% of the population using community water systems to receive optimally fluoridated water” [9].

Even though people often disregard the severity of cavities, high cavity rates present a barrier to proper health for billions of people worldwide. Fluoridation is an efficient method to address this public health concern in countries of varying economic status. While the debate over whether or not fluoride should be included in water continues due to its various harmful effects, fluoridation remains an accessible and beneficial option for many.


  1. Centers for Disease Control and Prevention. (2021, October 1). Water fluoridation basics. Centers for Disease Control and Prevention. Retrieved November 14, 2021, from

  2. Oral-B. (2021). What are Dental Caries? Treatments, Signs, and Symptoms. Oral-B.

  3. World Health Organization. (2019). Inadequate or excess fluoride. World Health Organization. Retrieved November 14, 2021, from

  4. Whitehead, N. (2019, July 19). Study: Sugar rules the world and ruins teeth. NPR. Retrieved November 14, 2021, from

  5. Fluoride: Topical and systemic supplements. American Dental Association. (n.d.). Retrieved November 26, 2021, from

  6. Renson C. E. (1986). Changing patterns of dental caries: a survey of 20 countries. Annals of the Academy of Medicine, Singapore, 15(3), 284–298.

  7. Fawell, J. et al. (2006). Fluoride in Drinking Water. World Health Organization.

  8. Lennon, M.A. et al. Fluoride. World Health Organization.

  9. Centers for Disease Control and Prevention. (2020, December 2). Coordinate Community Water Fluoridation Programs. Centers for Disease Control and Prevention. Retrieved November 26, 2021, from


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