Dental fillings that contain mercury are generally safe for most adults and children

Getting a filling is a common dental procedure that is used to treat cavities and protect teeth damaged by tooth decay.

There are several types of filling material currently available to repair cavities, including tooth-colored composite fillings and silver-colored amalgam fillings, which contain liquid (elemental) mercury.

A VERIFY viewer recently asked our team in a text message if the mercury found in dental amalgam fillings is bad for your health. 

THE QUESTION

Are dental fillings that contain mercury harmful?

THE SOURCES

• U.S. Food and Drug Administration (FDA) 
• Environmental Protection Agency (EPA)
• American Dental Association (ADA)
• Cleveland Clinic
• Kelly Johnson-Arbor, MD, co-medical director of the National Capital Poison Center and the medical director of hyperbaric medicine at MedStar Georgetown University Hospital
• Michael Kostrov, DMD, general dentist at Comprehensive Dental Care in Washington, D.C.

THE ANSWER

Dental amalgam fillings that contain mercury are generally considered safe for most adults and children over the age of 6.

But certain individuals, including people who are pregnant or planning to become pregnant, nursing mothers, children under the age of 6, people with a known allergy to mercury, and people with a neurological impairment or kidney dysfunction, should avoid getting dental amalgam fillings if possible and appropriate, according to the FDA.

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WHAT WE FOUND

Dental amalgam fillings, which contain elemental mercury, are generally safe for most people — but the process of getting them installed, removed or replaced could lead to potential mercury exposure, which could be harmful for certain groups.

Dental amalgam is a mixture of metals, consisting of elemental mercury and a powdered alloy composed of silver, tin and copper. Approximately 50% of dental amalgam is elemental mercury by weight, according to the U.S. Food and Drug Administration (FDA). Elemental mercury is different from the form of mercury found in fish, known as methylmercury.

Dental amalgam is generally offered as a lower-priced alternative to composites. The Cleveland Clinic said in 2020 that there are millions of amalgam dental fillings in use and they continue to be placed in dental schools, clinics and hospitals all over the world.

When a new dental amalgam filling is placed or an old filling is removed, they can release small amounts of mercury in the form of a vapor (gas), depending on the number and age of existing fillings, and whether the person did things such as tooth grinding and gum chewing, according to the FDA. During this time, patients and healthcare providers may experience a temporary increase in exposure to mercury vapor.

While there are no known health risks associated with swallowing small particles of dental amalgam, breathing in mercury vapors may be harmful in certain patients, according to the FDA. Exposure to high levels of mercury vapor, which may occur in some occupational settings, including dental offices, has been associated with adverse effects on the brain and the kidney.

“Elemental mercury can be toxic if you inhale it. It has a very, very low vapor pressure, which means that it vaporizes in the air very easily at room temperature. So if you heat up an amount of mercury to place a filling, for example, or to remove a filling, you actually cause it to vaporize even more. And because it's toxic through inhalation, if you breathe in those fumes, that's what can be dangerous,” Kelly Johnson-Arbor, MD, co-medical director of the National Capital Poison Center, told VERIFY.

But the FDA and the Environmental Protection Agency (EPA) both say the mercury in dental amalgam fillings is generally considered safe for most adults and children over the age of 6. The American Dental Association (ADA) also says that dental amalgam has served as a “safe, durable and affordable material in restorative dentistry” for more than 150 years.

The FDA recommends that certain high-risk individuals, such as people who are pregnant or planning to become pregnant, nursing mothers, children under the age of 6, people with a known allergy to mercury, and people with a neurological impairment or kidney dysfunction, should avoid getting dental amalgam fillings “if possible and appropriate.”

“Little information is known about the potential health effects of mercury vapor exposure from dental amalgam on these groups of people,” the FDA says on its website. “Certain people may be more susceptible to the effects of exposure to mercury from dental amalgam and may be at greater risk for adverse health effects.”

But if you have dental amalgam fillings and are concerned about the amount of mercury found in them, Michael Kostrov, DMD, a general dentist at Comprehensive Dental Care in Washington, D.C., Johnson-Arbor, and the FDA do not recommend having the fillings removed or replaced.

“Removing intact amalgam fillings results in unnecessary loss of healthy tooth structure and exposes you to a temporary increase in mercury vapor released during the removal process,” the FDA says. “Intact amalgam fillings in any individual, including the sensitive groups, such as pregnant/nursing mothers and children, should not be removed for the purpose of preventing any disease or health condition, unless considered medically necessary by a health care professional.”