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Is Fluoride Dangerous?

girl brushing teeth

by Amy Spangler
May 24, 2013

Will using fluoridated water or fluoride toothpaste pose a danger to my child's health?

Updated February 18, 2014

Fluoride is often described as nature’s cavity fighter. Giving your baby the right amount of fluoride each day after her teeth start to erupt (usually between 6 and 12 months of age) can prevent tooth decay. But too much fluoride can discolor newly formed teeth causing white or gray spots to appear on the tooth surface—a condition known as fluorosis. Once teeth are formed (around 8 years of age) there is no risk for fluorosis. In the meantime, knowing how much fluoride to give and when can be tricky.

Most children and adults get their daily dose of fluoride from fluoridated toothpaste, mouthwash, and water. Fluoride occurs naturally in water, but the level can be very low (less than 0.2 mg/L) or very high (more than 2.0 mg/L), so communities adjust the local water supply by adding or removing fluoride.

Infant formula manufacturers intentionally keep fluoride levels in infant formula low to guard against formula-fed babies getting too much fluoride when their formula is mixed with fluoridated water. When powdered or concentrated liquid infant formula is consistently mixed with fluoridated water, exclusively formula-fed babies can get fluorosis. To prevent fluorosis, parents are cautioned to use low-fluoride or fluoride-free bottled water (labeled as de-ionized, purified, demineralized, or distilled) when mixing infant formula for some of their child’s feedings each day. Parents can also use ready-to-feed formula that doesn’t require mixing with water. But be aware that ready-to-feed formula is much more costly than powdered or concentrated liquid formula. The best way to prevent fluorosis is to monitor your child’s fluoride intake.

Tips for monitoring your child’s fluoride intake:

  • Know your water’s fluoride level. If you live in a state that participates in the Centers for Disease Control and Prevention (CDC)’s My Water’s Fluoride program you can check your water system’s fluoride level online or contact your local water supplier. If your drinking water contains more than 2.0 mg/L, the CDC recommends that you get your drinking water from another source.
  • Limit the use of fluoride toothpaste. Children ages 6 months to 3 years are at risk of swallowing toothpaste used for brushing and ingest too much fluoride, so the American Dental Association (ADA) and American Academy of Pediatric Dentists (AAPD) recommend only a “smear” of toothpaste (about the size of a grain of rice) at this young age. From 3 to 6 years old, they recommend only a “pea-sized” amount. Encourage children to “rinse and spit” as soon as they are developmentally able.
  • Avoid fluoride mouthwash. Fluoride mouthwash isn’t nearly as effective as fluoride toothpaste in fighting cavities, so it should not be used in children under the age of 6 years, and then only in children who are at high risk for tooth decay.
  • Check with your child’s dentist before taking fluoride supplements. Fluoride supplements (liquids, tablets, and lozenges) can increase the risk of fluorosis and should be used only if prescribed by your child’s dentist.
  • Get yearly check-ups. The AAP and the American Academy of Pediatric Dentistry recommend that every child see a dentist annually beginning around 1 year of age.

It’s easy to be swayed by media reports into believing that fluoride is dangerous, when in fact it’s not. Parents simply need to know how much fluoride to give and when. For more information on fluoride safety see, “Water Fluoridation Still Controversial After 80 Years” and “Antifluoridation Bad Science.”

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