Fluoride Treatment: Uses, Benefits & Risks

What is Fluoride?

Fluoride is a widespread mineral found in water, rocks, soil, and living things. Your bones and teeth contain fluoride.

The right dosage of fluoride can strengthen enamel and prevent tooth decay. For this reason, it’s found in many products like toothpaste and mouthwash.

Since 1945, fluoride has also been added to drinking water in many parts of the world. Research has shown this reduces tooth decay in children.^{1, 2}

However, excessive amounts of fluoride can cause health problems. In some countries, drinking water has to be treated to reduce its naturally high fluoride levels. The benefits and risks of water fluoridation have been debated since it began.^{1, 3, 4}

Benefits of Fluoride

Fluoride can remineralize tooth enamel, preventing cavities from forming. It also inhibits cavity-causing bacteria.⁵ It may help offset the damaging effects of the modern diet, which is high in sugar.

Fluoride should be topically absorbed to maximize its effectiveness. In other words, the teeth must be exposed to it directly. 

However, fluoridated dental products aren’t always available, and they can be dangerous for young children due to how concentrated they are. Because of this, water, milk, or salt fluoridation is most likely to benefit:^{2, 7}

• Children
• People in areas with very low natural fluoride
• Communities with poor oral hygiene and limited access to dental care

Uses of Fluoride

Fluoride prevents tooth decay by remineralizing the enamel before it worsens. It forms a compound called fluorapatite, which gets incorporated into your tooth enamel.

The use of fluoride to strengthen teeth is called fluoride therapy. Fluoride can be applied directly to teeth or consumed as a supplement.

Many dental products contain fluoride, including:

• Toothpaste
• Mouth rinses
• Fluoride gels and foams
• Fluoride varnishes (applied by dentists)
• Lozenges or oral supplements

These products allow your teeth to be exposed to fluoride in a controlled way. Drinking water often naturally contains fluoride or has fluoride added to it (see below).

Water Fluoridation

A widespread but controversial form of fluoride therapy is water fluoridation. This refers to adding a small amount of fluoride to the public water supply.

Many global health organizations consider water fluoridation safe and effective for preventing tooth decay. However, high concentrations of fluoride are hazardous to human health. Some researchers argue that the risks of water fluoridation outweigh the benefits.^{5, 6}

Fluoride can also be consumed in other ways. In some countries, fluoride is added to store-bought milk and salt instead of the water supply.⁴

Other Uses

Outside of fluoride therapy for teeth, fluoride and similar compounds are also used in:

• Biochemical research
• Steel production
• Aluminum smelting
• Water-repellent clothing
• Pesticides and cleaning agents

Health Risks of Fluoride

In higher doses, fluoride is toxic. Excessive consumption can cause a range of adverse health effects:

Fluoride Poisoning

Ingesting too much fluoride in a short amount of time can cause symptoms such as:

• Nausea
• Vomiting
• Diarrhea

Acute fluoride poisoning is a temporary condition. However, exposure to excess fluoride over a longer time period may cause lifelong health issues (see below).

Dental Fluorosis

Children who are exposed to excessive amounts of fluoride can develop dental fluorosis.

Fluoride incorporates itself into enamel tissue, which is rarely a problem for adults. But in children whose teeth are still developing, it can cause the enamel to develop abnormally, leading to:

• Weak enamel
• White streaks
• Yellow or brown stains
• Widespread pitting of the enamel (in severe cases)

Children with fluorosis have a lower risk of tooth decay, but the strength and appearance of their teeth can be compromised. 

Skeletal Fluorosis

Excessive fluoride exposure can also lead to skeletal fluorosis. This condition damages the parathyroid glands. These are glands in the neck that control calcium levels.

Skeletal fluorosis may cause the following in older adults:

• Joint stiffness
• Joint pain
• Fractures

These problems occur because the bones have been weakened, similar to the enamel in children with dental fluorosis.

Other Health Conditions

Long-term or excessive fluoride exposure has been linked to other health conditions, including:^{1, 5, 6, 8}

• Arthritis
• Kidney disease
• Thyroid problems
• Abnormal brain development in children

Some of the research linking fluoride to these problems is controversial. More research is needed to draw a firm conclusion, especially regarding fluoride’s effects on children’s brain development.^{1, 6}

Fluoridated Water Controversy

Research has shown topical fluoride to be effective at strengthening tooth enamel.^{2, 4} However, water fluoridation has been debated since it began in 1945.

Supporters of water fluoridation, such as the World Health Organization and the US Department of Health and Human Services, argue that:

• Fluoride is effective at reducing cavities, especially in children.
• Without water fluoridation, high-risk communities may suffer from worse dental health.
• Water fluoridation is more cost-effective than dental care.⁹
• Ingestion of fluoride in water is safe at recommended levels (0.7 milligrams per liter, or about 0.7 parts per million).^{5, 10}

On the other hand, the European Commission finds no advantage to water or food fluoridation over the topical fluoride found in dental products.¹¹

Some countries, such as Estonia, have naturally high fluoride levels in their drinking water and have to reduce it for public safety.¹² Other countries, like Israel, have banned water fluoridation.¹³

Why Do Some People Oppose Fluoridating Water?

Opponents of water fluoridation make the following points:

• The benefits of fluoride are primarily topical, so it makes more sense to apply it directly to the teeth (with products like toothpaste).^{4, 5}
• Different people drink different amounts of water, so fluoridating water means some people will get a higher dose than they need.⁴
• Many countries don’t fluoridate their water and have still seen a decrease in cavities due to high-quality dental care.^{3, 11}
• Water fluoridation isn’t more cost-effective than dental care when the costs of treating dental fluorosis are factored in.⁹

If you’re concerned about fluoride in your water, reverse osmosis filters can remove it. You can also opt for bottled water. However, the fluoride content of bottled water may be unknown.

The Centers for Disease Control and Prevention (CDC) has a Water System Information Tool. This allows you to see the fluoride levels in your area.

Summary

Fluoride is a mineral found throughout nature, including inside your body. Small doses of fluoride can make your enamel stronger and prevent cavities.

Various dental products, including toothpaste and mouth rinses, contain fluoride. In addition, many countries add fluoride to their drinking water or food items like milk and salt.

However, fluoride is hazardous to human health in high doses. Some researchers question the benefits and risks of adding fluoride to food or water.