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Fluoride helps kids develop healthy, strong teeth. It also helps prevent cavities (tiny holes in the teeth).

What Is Fluoride?

Fluoride (FLOOR-ide) is a mineral found in water sources and soil. Fluoride is added to the water in the United States and other countries. It is also found in some toothpastes, mouth rinses, and vitamin supplements.

What Does Fluoride Do?

Fluoride strengthens teeth enamel. The enamel is the hard outer covering of the teeth. By keeping the enamel strong, fluoride helps prevent cavities.

How Does Fluoride Work?

Cavities are caused by tooth decay. Tooth decay is caused by some types of bacteria (germs) in the mouth. These bacteria make acid that can break down tooth enamel. Fluoride prevents the acid from breaking down the enamel. It also helps teeth damaged by acid to repair themselves. Fluoride cannot repair cavities, but it can reverse some tooth decay and prevent new cavities.

How Do I Know if There’s Fluoride in My Drinking Water?

If you get your water from a public source, you can find out if there is fluoride in it by:

  • asking your dentist or doctor
  • calling your local water utility company
  • calling the public health department
  • checking the CDC’s website

If you get your water from a private sources, the company can tell you if it has fluoride. If your family only drinks bottled water, be sure to check if there is fluoride in it.

If you have well water, its fluoride level can be tested at a laboratory or public health department.

Does My Child Need Fluoride Supplements?

In general, kids under the age of 6 months do not need fluoride supplements. After that, your doctor or dentist may prescribe fluoride supplements if:

  • You live in an area that does not have fluoride in the water.
  • Your child drinks only bottled water.

Your doctor or dentist can help you decide if your child needs fluoride supplements. The supplements are available as drops or tablets. The dose depends on how much fluoride is in the water your child drinks and your child's age.

Is Fluoride Safe?

Fluoride is safe, but getting too much can cause dental fluorosis. Dental fluorosis (fluh-ROE-siss) causes changes in how tooth enamel looks. Typically, it leads to white spots on the teeth. Most kids who get fluoride do not get dental fluorosis. It happens when kids under 8 years old get too much fluoride while their teeth are developing.

Experts have not found any other health problems from fluoride.

Very rarely, a child can get fluoride poisoning from taking in a lot of fluoride in a short time (for example, from eating toothpaste or fluoride supplements). Generally, this isn’t not serious, but call your doctor or the poison control center (1-800-222-1222) if you think your child ate a large amount of fluoride.

Be sure to keep toothpaste, supplements, mouth rinses, and other fluoride-containing products out of kids' reach or in a locked cabinet. Also, supervise young kids when they brush their teeth to prevent swallowing of toothpaste or other fluoridated products.

How Do I Make Sure My Child Gets the Right Amount of Fluoride?

To make sure your child gets the right amount of fluoride:

  • Follow your doctor’s or dentist’s advice on whether your child needs to take a fluoride supplement.
  • If your doctor or dentist prescribes fluoride, be sure to give the dose exactly as recommended.
  • If your fluoride level is high in your drinking water, talk to your doctor or dentist about whether your children should drink bottled water (including if you have a baby that drinks formula mixed with water). 

Babies whose teeth have not come in yet do not need fluoride toothpaste.

  • For children under 3 years old: Brush your child’s teeth twice a day with a small smear (the size of a grain of rice) of fluoride toothpaste.
  • For children 3 years old and older: Help your child brush twice a day using a pea-size amount of fluoride toothpaste. 

Follow your doctor’s or dentist’s advice on whether your child should use a mouth rinse that contains fluoride. Kids under age 6 should not use rinses with fluoride because they may swallow it. 

What Can I Do to Keep My Child’s Teeth Healthy?

Making sure your child gets the right amount of fluoride is one way to help your kids have healthy teeth. Your family dentist or pediatric dentist (one who specializes in the care of children's teeth) is a great resource for information about dental care and fluoride needs.

Other things you can do:

  • Take your child to the dentist within 6 months of the first tooth coming in OR by 1 year of age (whichever comes first).
  • Take your child to the dentist twice a year or as recommended by your dentist or doctor.
  • Ask your dentist whether a varnish (a seal that is “painted” on your child’s teeth) is needed.
  • Don't leave a bottle of milk or formula in the crib with your child.
  • Limit juice. If you do give juice, give it in a cup (not a bottle or sippy cup) with meals and limit it to 4–6 ounces per day (none for babies under 1 year old). Brush your child's teeth when finished.
  • At 1 year old, wean your child from the bottle. Give a cup instead.
  • If your child is thirsty between meals or likes to sip throughout the day or at night, give water only.
Medically reviewed by: Amy W. Anzilotti, MD
Date reviewed: January 2021