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Are Dental Amalgam Fillings Harmful?

amalgam dental filling

I am often asked by patients if they should have existing amalgam fillings removed (often called silver amalgam fillings, or just silver fillings) because they contain mercury – a known toxin. I will discuss amalgam fillings and answer that question for you.

What Is Amalgam?

Amalgam is a metal consisting of mercury, silver and several other metals. When first mixed, it is soft and can be packed into a tooth, where it sets up hard in a few minutes. Amalgam does not bond to the tooth and is held in place by mechanical undercuts.

The advantage of amalgam is that it is easy to place, relatively inexpensive, and durable.

The disadvantages of amalgam are:

  • It is not esthetic – it looks black in the mouth
  • It expands and contracts with temperature changes and thus cracks teeth.
  • It weakens teeth.
  • It contains mercury, a known toxin.

Are Amalgam Fillings Safe

There has been an ongoing debate for many years among dentists, patients, and government health organizations about the potential harmful effects of the mercury in amalgam. The question is, can you get mercury poisoning from amalgam fillings?

Proponents of amalgam feel that the mercury is bound into the metal and very little escapes into the body. This is the position of the American Dental Association and most other agencies. That was my thinking as well until something happened almost 20 years a go.

I was sitting in a seminar listening to the speaker extolling the theory that amalgam is basically harmless, and all the reasons to use it – namely that it’s the cheapest, easiest restoration to place. At some point he also explained the strict guidelines that dentists must follow for the storage and disposal of amalgam.
Any left over amalgam must be stored in a sealed container under water, and it must be disposed of by certified hazardous waste handlers.

While everyone around me was scribbling notes, I sat there with a puzzled look on my face. If amalgam is so harmless, then why does it have to be treated like hazardous waste… unless it’s in someone’s mouth. It seemed to me that according to this speaker, The American Dental Association, the FDA and other agencies… the only safe place to store amalgam is in the human body!

That was the end of me using amalgam, and I haven’t placed an amalgam filling in almost 20 years. But it is still widely used in dental offices across the country. The truth is that we may never know whether amalgam is safe or not, but the reality is that there is no reason to place amalgam fillings any more, since we have better alternatives available that don't contain toxic mercury.

Should You Have Your Amalgam Fillings Removed?

This question about amalgam filling removal comes up a lot with people who are concerned about the toxicity of mercury in their mouths, and wondering if they should have the fillings replaced - especially if they have a chronic health condition like Multiple Sclerosis, ALS, Rheumatoid Arthritis or others.

Generally my philosophy is that I will replace amalgam fillings with resin or porcelain if the patient wants it. But I caution patients not to expect any improvement in underlying health problems.

My personal belief is that after fillings have been in place for a fair amount of time, much of the mercury that could leach out has already done so. (but I have no scientific proof of that). So my normal procedure is to wait until the filling is failing, and then replace it with a different material.

In summary, I would say that if you are uncomfortable with the thought of having mercury containing fillings in your mouth, then go ahead and have them replaced, particularly if they are older. But do not have the expectation that this will resolve underlying health problems as there is no solid proof that amalgam removal will help. Granted, you can find many stories of this happening, but no solid studies are available.

How Can Amalgam Fillings Be Safely Removed

Dental fillings are removed by grinding them out with a high speed drill with a water spray. Contamination is minimized by holding a high speed suction right next to the tooth. This is the standard procedure in most offices.

There are removal methods that make amalgam removal even safer. One is by placing a rubber dam which is simply a piece of latex that is placed over the tooth to isolate it from the rest of the mouth. This is quite effective in minimizing any amalgam dust being swallowed during the procedure.

Another method is by using a device called the ISOLITE or something similar. This is a great invention that simultaneously acts as a bite block to rest your jaw on, retraction of the tongue and cheek, and suction. This is also effective in minimizing amalgam being swallowed or aerosolized. You can ask your dentist to use one of these methods if you are concerned.

Amalgam Filling Vs Composite Filling (Resin Filling)

Smaller amalgam silver fillings can be replaced with composite resin fillings, however if it is a large filling, it it is best replaced with a porcelain crown for maximum strength and longevity. This is especially true because old, large amalgam fillings have no doubt already caused cracks in the underlying tooth structure.

The advantages of composite fillings are:

  • Better esthetics as they match the tooth color.
  • They are bonded to the tooth so there is less leakage.
  • They do not crack teeth like amalgam.
  • They better prevent teeth from cracking in the future.
  • They don't turn the existing tooth structure dark like amalgams.

The disadvantages of composite fillings are:

  • They are more difficult to place.
  • They are more technique sensitive, so they need to be placed carefully.
  • They are more expensive because of the above.

Bottom line...

If you do have amalgam fillings replaced for any reason, I recommend that you not have it replaced with another amalgam.

As with many health situations, whether to have your functioning amalgam fillings removed or not is a personal decision best made between you and your dentist. Certainly if the fillings are older I would recommend it, as old amalgams cause many problems like inflammation of the gum tissues, leakage, decay, and cracking of teeth.