FDA Opposes Use of ‘Silver’ Dental Filings for Parkinson’s Patients, Others

New guidance from the U.S. Food and Drug Administration (FDA) recommends that dental amalgams — a silver-colored tooth filling that contains mercury — no longer be used with select groups of people, including those with neurological disorders like Parkinson’s, multiple sclerosis, and Alzheimer’s.

Dentists should instead use mercury-free alternatives, such as composite or glass ionomer cement fillings, with these patients, and with children (especially those under age 6), pregnant and nursing mothers or women planning a pregnancy, people with poor kidney function, and those with mercury sensitivities or allergies.

“Our reviews and discussions,” the guideline states, “have generally arrived at the same conclusion: while the majority of evidence suggests exposure to mercury vapor 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 such as those who are hypersensitive to mercury.”

The agency cites uncertainties concerning long-term exposure to amalgams, the potential for mercury to convert to other harmful compounds in the body, and the effects of its accumulation in issuing the recommendation.

Its new guidance updates an FDA position issued in 2009 that moved amalgam fillings into a higher risk category (a class II device), but did not take a position against their use.

Often called silver fillings in the U.S., amalgam is a mixture of 50% pure mercury and a powdered alloy of silver, tin and copper. These fillings release small amounts of mercury vapor over time.

“While small inhaled amounts are generally not harmful to most people, this can pose an increased health risk to susceptible individuals. How much vapor is released may depend on the age of the filling and habits such as teeth grinding,” said Jeffrey E. Shuren, MD, an FDA office director, in a press release.

Because the highest mercury releases come from placing and removing amalgam fillings, the FDA recommends that people leave existing amalgams in place, unless it’s medically necessary to remove them.

“The FDA’s measures have the potential to protect millions upon millions of Americans from mercury in the mouth. But it is now important to ensure that the recommendations are implemented,” said Charlie Brown, national counsel of Consumers for Dental Choice and president of the World Alliance of Mercury-Free Dentistry.

The alliance’s campaign was influential in bringing the FDA to reconsider its position on amalgam fillings.

The American Dental Association continues to support the use of these fillings as safe and as less costly than composites or gold fillings.

“Because of their durability, these silver-colored fillings are often the best choice for large cavities or those that occur in the back teeth where a lot of force is needed to chew,” it states on a webpage. “It’s important to know that when combined with the other metals, it forms a safe, stable material. Be assured that credible scientific studies affirm the safety of dental amalgam” in use for more than 100 years.

The FDA, with this recommendation, moves the U.S. closer to current European standards, where governing EU bodies voted to ban use of dental amalgam for children under age 15, and for pregnant and breastfeeding women in 2018.

Draft legislation for a total phase-out of mercury-containing fillings is expected from the European Commission in 2022.

A full ban on the use of amalgam fillings is reported to be underway in select European countries, like Denmark and Sweden.