Instead of recommending a complete ban of dental amalgam, the U.S. Food and Drug Administration (FDA) is advising that high-risk individuals, such as pregnant women, avoid getting these fillings “whenever possible and appropriate.”
Those considered high risks are advised to receive nonmercury materials, such as composite resins or glass ionomer cement fillings. Previously, the agency warned that people in these groups may be at greater risk of adverse health events from mercury-containing fillings and suggested they talk to their dentists about alternatives, but the FDA stopped short of recommending they “avoid” them.
Though the agency maintains that the “majority of evidence suggests exposure to mercury vapour from dental amalgam fillings doesn’t lead to harmful health effects for most people, there may be some effects in people with certain health issues,” it said in a statement issued on September 24.
The FDA listed the following groups as high risk:
- Pregnant women and their developing fetuses
- Women who plan to become pregnant
- Nursing women and their newborns and infants
- Children, especially those younger than 6 years
- People with preexisting neurological diseases, such as multiple sclerosis, Alzheimer’s disease, or Parkinson’s disease
- People with impaired kidney function
- People with known heightened sensitivities or allergies to mercury or other dental amalgam components
- This is also the first time the FDA has listed multiple sclerosis, Alzheimer’s disease, and Parkinson’s disease in its guidance.
The FDA made these recommendations after evaluating published literature and considering comments from healthcare officials and the public that were received at the end of 2019. Some expressed concern about the cumulative effect on underserved communities of mercury vapour exposure from dental amalgam.
Many factors and uncertainties surrounding how much mercury vapour is released from dental amalgam affected the current decision. The amount of vapour released can depend on a filling’s age, as well a person’s habits, such as teeth grinding. Also, there are still uncertainties about the following:
The effects of long-term exposure to dental amalgam on the high-risk groups. The potential for mercury in the dental amalgam to convert to other mercury compounds in the body whether the accumulation of mercury in some bodily fluids and tissues results in other unintended health outcomes.
Despite the update, the agency still does not recommend removing or replacing existing amalgam fillings that are in good condition unless it is medically necessary.