Patient education: Fluoride (The Basics)

What is fluoride? — 

This is a natural mineral often found in drinking water. It is good for teeth when the right amount is absorbed into the body as teeth are developing. Fluoride can help lower the risk of cavities by helping to keep the outer layer of teeth strong.

Fluoride is in many kinds of toothpaste. There are also special fluoride mouth rinses.

Some fluoride is also found in food and natural water sources. Some areas add fluoride to drinking water. This helps lower the risk of cavities for people in the community. It is especially important for people who might not have access to good dental care.

How does fluoride work? — 

Fluoride helps make the outer layer of teeth, called the "enamel," stronger (figure 1).

After eating or drinking, bits of food and sugar are left on teeth. Germs in the mouth combine with food and sugar to make acid. The acid can eat away the protective enamel of the tooth and cause tooth decay.

Fluoride can help make teeth stronger:

●From the inside – When you drink water with fluoride in it, the fluoride enters your bloodstream. It becomes part of your teeth as they develop. This is also how a fluoride supplement works.

This kind of fluoride is especially important when a young person is still forming permanent teeth. Before teeth break through the gums, fluoride can help make the enamel stronger and more resistant to tooth decay.

●From the outside – After teeth come through the gums, they can absorb fluoride from toothpaste or a mouth rinse. When you drink water with fluoride in it, some fluoride is absorbed as the water washes over your teeth. Your teeth also absorb fluoride when you get fluoride treatment at the dentist.

This kind of fluoride helps rebuild weak places in the tooth's enamel. This can reverse signs of decay.

●For people with receding gums – It can help prevent decay on the root of the tooth that is not protected by enamel.

Can fluoride be harmful? — 

If a person consumes a lot of fluoride, this can cause health problems. But the amount typically added to drinking water is not enough to cause harm. Evidence shows these levels of fluoride are safe and work well to help prevent cavities.

In young children, too much fluoride can cause faint white lines or streaks on permanent teeth as they develop. This is called "fluorosis."

What else should I know?

●To help young children avoid swallowing too much fluoride, use small amounts of toothpaste:

•Use a smear of toothpaste for infants and toddlers under 3 years old (picture 1).

•Use a pea-size amount of toothpaste for older children (picture 2).

●Most bottled waters do not contain fluoride. Some kinds of water filters can lower the amount of fluoride in the water. Well water also does not contain fluoride.

More on this topic

Patient education: Tooth decay in adults (The Basics)
Patient education: Tooth decay in children (The Basics)
Patient education: Toothache (The Basics)
Patient education: Starting solid foods with babies (The Basics)

Patient education: Starting solid foods with babies (Beyond the Basics)