Are Silver Fillings Safe, and Should You Have Them Replaced?

You can see it when you open wide in the mirror: a dark gray patch on a back tooth, placed years ago. Then you read that it is half mercury. Are amalgam fillings safe? For most people, a silver filling in good condition is better left where it is than drilled out. The FDA does not recommend removing one that is intact, and its reasons are worth knowing.

Let me walk you through what the filling is made of, who should avoid it, and why the world is phasing it out anyway.

What is actually in a silver filling?

Dental amalgam starts as liquid mercury mixed with a powdered alloy of silver, tin and copper. According to the FDA, about half of the finished filling is mercury by weight. The mercury reacts with the alloy and sets into a hard metal you can chew on.

Setting does not lock in every atom. The FDA's guide for patients says amalgam releases small amounts of mercury as a vapor. How much depends on how many fillings you have, how old they are, and habits like grinding your teeth or chewing gum. Rubbing the surface, which is what grinding and chewing do, frees a little more.

The route into the body matters. The FDA says there are no known health risks from swallowing small particles of amalgam, so the concern is breathing in the vapor. People with several fillings can have slightly higher mercury levels in their blood or urine. The FDA says those levels usually stay within a range considered safe. It adds that studies have not shown conclusive evidence of harm in the general population.

You may also know about mercury in fish. That is methylmercury, a different compound, and the American Dental Association notes that fillings do not contain it.

Are amalgam fillings safe for everyone?

Not for everyone equally. On September 24, 2020, the FDA named groups who may face higher risk from mercury vapor, starting with pregnancy and early childhood:

• women who are pregnant or planning to become pregnant
• nursing women and their newborns and infants
• children, especially those younger than six

The other three involve health conditions:

• people with a neurological disease such as multiple sclerosis, Alzheimer's or Parkinson's
• people with impaired kidney function
• people with a known allergy or sensitivity to mercury or the other metals in amalgam

The FDA did not find proof that amalgam harms these groups. It said little is known about how mercury vapor affects them, so it advised them to avoid new amalgam when possible and appropriate. That advice is about the next filling, not the ones already in place.

Why is removing a good silver filling not recommended?

Two things happen when a sound filling is drilled out, and both work against you.

First, the drill grinds the metal into fine particles. The FDA says removal can briefly raise your exposure to mercury vapor, and the exposure of the people treating you. So a step taken to lower your mercury exposure raises it for a while.

Second, the drill cannot take out the metal without taking some tooth with it, so the new filling sits in a larger hole. Repeat that over the years and the walls of the tooth get too thin to hold a filling. At that point the tooth needs an onlay or a crown instead.

That is why the FDA says intact amalgam fillings should not be removed to prevent disease. That includes pregnant and nursing mothers and children, unless a health professional considers removal medically necessary.

If the FDA says leave them in, why is amalgam being phased out?

In November 2025, the countries in the Minamata Convention on Mercury agreed to end the use of dental amalgam by 2034. The Convention calls that decision a milestone in reducing mercury pollution. The treaty's stated objective is protecting health and the environment from mercury emissions and releases.

The EPA explains where dental mercury escapes. Scrap amalgam goes down chairside drains when a new filling is placed or an old one is drilled out. At the treatment plant, the mercury often ends up in sludge that is burned, buried or spread on land.

The EPA calls mercury a potent neurotoxin that builds up in fish and shellfish. It also names dental offices as the main source of mercury reaching wastewater treatment plants. Its 2017 rule requires offices that place or remove amalgam to run a separator that catches the scrap before it reaches the sewer.

In July 2026, the federal Department of Health and Human Services announced that it had urged every state Medicaid director to phase out amalgam fillings. The lever is coverage: states were asked to restrict or end Medicaid payment for them. HHS said amalgam poses health and environmental risks, pointing to the higher-risk groups the FDA lists. The notice is about what Medicaid pays for when a new filling is placed, and it says nothing about removing fillings already in place.

For a filling already in your mouth, the FDA's current advice still stands: if it is intact, leave it in place.

What do we do about silver fillings at our office?

We place tooth-colored composite only, and the reason is structural rather than cosmetic. Composite bonds to the tooth, so we only remove what is decayed. Amalgam does not bond and is held in by shape, which means cutting away extra healthy tooth to lock it in.

To be straight about the tradeoff, the FDA notes composite may not last as long as amalgam in back teeth under heavy biting force. Resins carry their own concern too, a sensitivity some people have to chemicals called methacrylates.

If your silver fillings are sound, they typically do not need replacing just to change their color. We recommend replacing one when it is failing or when decay has started underneath it. A gray shadow beside an old filling is not always decay, as our post on a black spot on your tooth explains.

What usually ends a filling is the margin, the seal where filling meets tooth, opening enough to let bacteria back underneath. We check that margin at every visit, which is how a failing filling gets caught while the repair is still small. Our fillings page explains how a composite repair is done.

The FDA names one more reason to talk about removal. If you have a mercury allergy or sensitivity, or a neurological or kidney disease, it says to discuss removal with your dentist or physician.

Common questions about silver fillings

I am pregnant. Should I have my silver fillings taken out?

The FDA says intact amalgam fillings should not be removed to prevent disease, even in pregnant and nursing mothers. The exception is when a health professional considers removal medically necessary. Removal briefly raises mercury exposure. For a new filling, the FDA advises people in this group to avoid amalgam when possible, and we place tooth-colored composite.

Can I choose to replace a sound silver filling anyway?

Yes, the decision is yours, so ask us first what the tooth would lose. The drill takes healthy tooth along with the old metal, and each replacement leaves a larger hole.

What should you do about your silver fillings?

If they are intact, keep up your checkups, because that is where the edges get looked at.

Call sooner if a filling feels rough or sharp to your tongue, floss shreds on it, or the tooth hurts when you bite. To ask a question or set up a visit, call us at (540) 288-2800 or send a message through our contact page.