Fluoride is a mineral in your bones and teeth. It’s also found naturally in the following:

  • water
  • soil
  • plants
  • rocks
  • air

Fluoride is commonly used in dentistry to strengthen enamel, which is the outer layer of your teeth. Fluoride helps to prevent cavities. It’s also added in small amounts to public water supplies in the United States and in many other countries. This process is called water fluoridation.

Read on to learn more about the use of fluoride and the controversy surrounding its safety.

In the context of human health, fluoride is mainly used to improve dental health. You can sometimes find it in your local water supply and in many over-the-counter (OTC) products, including:

  • toothpaste
  • mouth rinses
  • supplements

If you tend to get a lot of cavities, your dentist might suggest using a prescription mouth rinse with fluoride. These rinses usually have a higher concentration of fluoride than OTC options do.

Fluoride is also used:

  • in medical imaging scans, such as PET scans
  • as a cleaning agent
  • in pesticides
  • to make Teflon, steel, and aluminum products

Fluoride is beneficial to teeth because it helps to:

  • rebuild (remineralize) weakened tooth enamel
  • slow down the loss of minerals from tooth enamel
  • reverse early signs of tooth decay
  • prevent the growth of harmful oral bacteria

When bacteria in your mouth break down sugar and carbs, they produce acids that eat away at the minerals in your tooth enamel. This loss of minerals is called demineralization. Weakened tooth enamel leaves your teeth vulnerable to bacteria that cause cavities.

Fluoride helps to remineralize your tooth enamel, which can prevent cavities and reverse early signs of tooth decay.

According to the Centers for Disease Control and Prevention (CDC), the average number of missing or decaying teeth in 12-year-old children in the United States dropped by 68 percent from the late 1960s through the early 1990s. This followed the introduction to, and expansion of, fluoridated water in communities, and the addition of fluoride to toothpastes and other dental products.

While fluoride is a naturally occurring compound, it can still cause side effects when consumed in large doses. In the United States, the amount of fluoride that’s added to water is usually around 0.7 parts per million (ppm), the maximum allowed as of 2015.

Dental fluorosis

Dental fluorosis happens when you consume too much fluoride while your teeth are still forming under your gums. This results in white spots on the surface of your teeth. Other than the appearance of white spots, dental fluorosis doesn’t cause any symptoms or harm.

It tends to affect only children under the age of 8 who have permanent teeth still coming in. Children are also more likely to swallow toothpaste, which contains significantly more fluoride than fluoridated water.

You can reduce your child’s risk of developing dental fluorosis by supervising them when they brush their teeth to make sure they aren’t swallowing large amounts of toothpaste.

Skeletal fluorosis

Skeletal fluorosis is similar to dental fluorosis, but it involves bones instead of teeth. Early symptoms include joint pain and stiffness. Over time, it can alter bone structure and cause the calcification of ligaments.

It tends to result from long-term exposure to high levels of fluoride, often in drinking water. Several things can cause excessive fluoride in water, including accidental contamination from fires or explosions. Some areas, including large parts of Africa and Asia, also have large geologic deposits of fluoride, which can contaminate water supplies.

There are also reported cases of skeletal fluorosis in the United States, though it’s rare. In the case of a 52-year-old American man with skeletal fluorosis, experts concluded it was likely due to swallowing toothpaste.

Researchers from around the world have conducted hundreds of studies that look at the safety of adding low concentrations of fluoride to drinking water. There’s no evidence that fluoride added to local water supplies in the United States causes any health problems, aside from the occasional mild case of dental fluorosis.

However, some people claim that fluoridated water causes a variety of health problems, including:

The research behind these claims is mixed. For example, a 2006 study found that childhood exposure to fluoridated water was linked to higher rates of bone cancer in males. However, a 2011 review and a 2016 study didn’t find any connection between the two.

Studies looking at the link between fluoride and low IQ scores in children also have mixed results. A 2012 review of existing research concluded that there may be a link between the two, but noted that more large, high-quality studies are needed.

If you’re concerned about your fluoride intake, you can reduce your exposure by:

  • finding alternative sources of drinking water, such as bottled water
  • using a fluoride filter, available on Amazon, for tap water
  • choosing fluoride-free toothpaste, which you can also find on Amazon

Not every city in the United States fluoridates its drinking water. The decision about whether or not to fluoridate is made by each city.

However, the CDC has a tool you can use to check your local water supply if you live in certain states. This tool will tell you whether your city fluoridates its water. If it does, you’ll also be able to see how much they add.

If your city doesn’t fluoridate its water, but you’re interested in the dental health benefits of fluoride, try:

  • brushing your teeth twice a day with a fluoride toothpaste
  • using a fluoride mouthwash once a day (not recommended for children under 6 years of age)
  • asking your doctor about a professional fluoride treatment

Fluoride is a naturally occurring mineral used in many dental products to strengthen tooth enamel and prevent cavities. It’s also added to the local water supplies in many American cities.

While the amount added to drinking water is considered to be relatively safe, exposure to high levels of fluoride may be linked to several health issues.

If you’re concerned about your fluoride intake, ask your local government about the fluoride in your city’s water. You can also opt for fluoride-free dental products, especially if you have young children.

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