Fluoride is a naturally occurring mineral that helps build strong teeth and prevent cavities.

For more than 70 years, most of the tap water in America has contained small amounts of fluoride to reduce tooth decay. The Centers for Disease Control and Prevention (CDC) say that fluoridated water has reduced tooth decay by about 25 percent.

Fluoride treatments may offer even more significant benefits to protect teeth. These treatments can be beneficial to people at risk of tooth decay but may not be right for everyone.

In this article, we look at the benefits and side effects of fluoride and fluoride treatment, as well as treatment recommendations.

a man lying down on a dentists chair as he gets a Fluoride treatmentShare on Pinterest
A person at risk of tooth decay may benefit from fluoride treatment.

Fluoride treatments are typically professional treatments containing a high concentration of fluoride that a dentist or hygienist will apply to a person’s teeth to improve health and reduce the risk of cavities. These in-office treatments may take the form of a solution, gel, foam, or varnish.

There are also some high-concentration fluoride treatments that people can use at home but only under the specific direction of a dentist.

The fluoride dentists use in these treatments is similar to the fluoride in toothpaste. However, the treatment contains much higher doses and may offer more rapid benefits.

Fluoride has several benefits for the teeth:

  1. It helps the body better use minerals, such as calcium and phosphate. The teeth reabsorb these minerals to repair weak tooth enamel.
  2. It joins into the tooth structure when teeth are developing to strengthen the enamel of the teeth, making them less vulnerable to bacteria and cavities for life.
  3. It slows or even reverses the development of cavities by harming bacteria that cause cavities.

When taken together, these benefits may help to:

  • reduce the risk of cavities
  • slow the growth of cavities
  • delay the need for expensive dental work
  • prolong the life of baby teeth
  • reduce the amount of time and money a person has to spend at the dentist

By preventing cavities and slowing the growth of bacteria, fluoride treatment may also:

  • prevent gum disease
  • reduce tooth pain
  • prevent the premature loss of teeth

Fluoride treatments can improve oral health, which, according to the World Health Organization (WHO), is a major predictor of overall health. Poor oral health can cause a range of other health conditions, including cardiovascular disease.

Some natural health advocates have expressed concern about fluoride at high doses. They also argue that fluoride is not safe for children, and even that fluoridated water may be dangerous.

However, it is a myth that fluoride treatments or fluoridated water cause widespread harm, although some people may experience some side effects, including;

Tooth discoloration

The most common side effect of fluoride is tooth discoloration.

Fluorosis is a condition that causes white streaks or other discoloration on the teeth. Fluorosis happens when a child ingests too much fluoride while their baby and adult teeth are developing under the gums. A child can develop fluorosis from birth to 8 years of age.

Discoloration is more common among young children who consume too much fluoride, either because they take fluoride supplements or swallow toothpaste.

The United States Public Health Service have set guidelines for the amount of fluoride that community drinking water should contain to help prevent tooth decay and minimize the risk of dental fluorosis. This level currently stands at 0.7 milligrams of fluoride per liter (mg/l) of water.

Experts recommend that even children who are too young to spit the toothpaste out themselves should use fluoridated toothpaste.

The American Academy of Pediatric Dentistry (AAPD) recommend that parents or caregivers use a minuscule amount of fluoridated toothpaste as soon as the child’s first tooth erupts. This protects a child’s teeth from cavities but does not put them at risk for fluorosis if the child accidentally swallows the toothpaste.

Allergies or irritation

A person may have an allergic reaction to fluoride or experience skin irritation, though these reactions are rare.

Toxic effects

Fluoride can be toxic if a person applies it incorrectly or at very high doses. However, this is unusual.

The American Dental Association (ADA) recommend the use of professional fluoride varnish on children under 6 years old. Fluoride varnish is the preferred option for young children, as they tend to swallow foams or gels, which may cause nausea and vomiting.

The CDC and the ADA recommend that frequent exposure to small amounts of fluoride every day is the best for reducing the risk of dental cavities for all ages.

For most people, this means drinking tap water with optimal fluoride levels and brushing teeth twice a day with fluoridated toothpaste. For children and adults who may be at a higher risk of cavities, fluoride treatments can provide extra benefits.


Dental cavities are the most common chronic childhood disease, five times more common than asthma.

The American Academy of Pediatrics (AAP) recommend fluoride treatment for all children as soon as their teeth begin to grow to prevent decay, pain, and future dental infections.

Dentists or doctors should repeat fluoride treatment every 3–6 months, depending on a child’s risk of cavities.

To reduce the risk of overexposure to fluoride, dentists also recommend the following:

  • Caregivers should brush children’s teeth with a small amount of fluoride toothpaste to reduce decay and minimize fluorosis risk. For children under 3 years of age, use no more than a smear or rice-sized amount of fluoridated toothpaste. For children aged 3–6, use a pea-sized amount of fluoride toothpaste.
  • Always supervise a child’s brushing to ensure they use the right amount of toothpaste, and try to get them to spit out most it if they can.
  • Children under 6 years old should not use at-home fluoride rinses, such as mouthwash, since they may swallow too much fluoride.


Fluoride recommendations for adults vary. Different studies have investigated a range of concentrations, doses, and frequencies of treatment.

If a person is at a moderate-to-high risk of developing tooth decay, professional fluoride treatment can help. Experts recommend that people at high risk of cavities get professional fluoride treatments twice a year.

People should discuss the risks and benefits of fluoride treatment with their dentists. It is essential to consider all sources of fluoride, including fluoridated toothpaste and mouthwash.

People who live in areas where the water does not contain fluoride may gain more significant benefits from regular fluoride treatments.

A sizeable body of evidence from randomized controlled trials, which are the gold standard of scientific studies, has established the benefits of topical fluoride treatments for preventing decay.

One systematic review reports that fluoride treatments, such as fluoride varnish, have a substantial effect on preventing cavities in both primary and permanent teeth.

Fluoride treatments are safe for most people. Even when there are side effects, those effects are usually minimal compared to the benefits. Most of the harm is likely to come from swallowing very high amounts of fluoride.

This does not mean that all fluoride treatments are safe for all people at all times. People with cavities or at risk of tooth decay should discuss their concerns with a dentist they trust.