What Can Happen to Your Teeth If You Get Too Much Fluoride

In large amounts, fluoride can be toxic. Because of this risk and small studies implying certain health effects, fluoride use has recently become controversial.

This can occur with accidental ingestion of large amounts. Fluoride poisoning causes digestive symptoms such as nausea, vomiting, diarrhea, and abdominal pain.

Rarely, fluoride poisoning progresses to more severe symptoms, affecting your heartbeat and breathing. It can lead to coma or death, but lethal doses are very high at 70-140 milligrams (mg) per kilogram (kg) of bodyweight, which is nearly impossible to reach with the amounts in tap water or toothpaste.

Children exposed to more fluoride than they need when their adult teeth are forming can develop fluorosis. This cosmetic issue causes teeth to become brown or discolored. It affects about 23% of the U.S. population.

With skeletal fluorosis, excess fluoride (over 1.5 parts per million—up to three times over safe limits) weakens bones, which can lead to damage and joint problems.

There’s a broad agreement that fluoride, as it occurs in most tap water and toothpaste, is safe to drink or brush with. 

Health authorities and professional dental organizations worldwide advocate for fluoride in water systems and toothpastes. Major proponents include:

• Centers for Disease Control and Prevention (CDC): The CDC has recommended community fluoridation since 2001.
• American Dental Association (ADA): This is the leading professional association of dentists in the U.S. The ADA recommends community fluoridation and its use in dental products.
• World Health Organization (WHO): A leading global health authority, the WHO supports community fluoride initiatives, while acknowledging the potential risks of overexposure.
• FDI World Dental Federation: The FDI World Dental Federation, an international organization of dentists and dental authorities, supports fluoride in community water and dental products.

While harmful effects may be possible with ongoing exposure to high levels of fluoride, the levels that people are exposed to in dental products and tap water typically don’t pose risks. And added fluoride offers individual and public health benefits.

In the U.S., fluoride has been added to community water supplies since 1945. In 1991, the CDC declared it one of the 10 greatest public health achievements of the 20th century. This is because fluoride in toothpaste and water strengthens tooth enamel and prevents decay.

The CDC’s Community Health Prevention Task Force found that adding fluoride to municipal water led to 15% fewer cavities. Reviewing data from 96 studies, researchers concluded that users of fluoride toothpaste had fewer cavities on average.

When you don’t get enough fluoride, you’re at higher risk of tooth decay and cavities, which require dental treatment. This can lead to:

• Tooth pain: As enamel erodes and the nerves inside your tooth are exposed, you may experience pain and sensitivity to hot or cold.
• Visible pits: Over time, cavities can form into visible pits and holes.
• Infection: If untreated, cavities can become infected. This can cause a tooth abscess, or a painful pocket of fluid around the tooth root.  
• Tooth loss: Tooth decay can damage the structure of the tooth, and untreated cavities are a leading cause of tooth loss.