Sunday, August 22, 2010

Should You Get Your Mercury-Containing Fillings Replaced?

Amalgam filling X-ray
I was chatting with my mother-in-law who was told by a friend to have all her fillings removed.

Most people know that conventional silver dental filings contain mercury, and that mercury is toxic. Dentists and governments around the world claim that mercury extracted from fillings is not important.  For example, FDA says that the mercury extract from dental fillings is too slow to be meaningful, and they have been saynig that for years.

The FDA put out a new "final" regulation on dental fillings in late July. Critics point out the the FDA has been wrong in the past. The FDA does have three warnings: dentists should be careful with when using it; the mercury amalgam vapor can be harmful; and people with known allergies to mercury should not use these fillings. These known allergies are typically rashes or swelling right next to the mercury and are not distant chronic effects.

Charlie Brown has nothing to
do with this article; It is a jokey
reference to filling activist
Charles Brown.
The final rule is an outrage," says Charles Brown, national counsel for Consumers for Dental Choice, a group against the use of mercury amalgams. ''It puts mercury 1 inch from a child's brain. It puts mercury directly to the fetus.''  Charles Brown is not a cartoon character, but rather an extremist with site called toxicteeth.org.

Some say that unscrupulous dentists alarm patients to have all their old fillings changed just to make money.  The good news is that mercury amalgam fillings are fading away; people are moving to porcelain. Some claim that removal of the mercury by heating it will only expose the patent to more harmful mercury vapor, and of course it will damage to tooth.

Metallic mercury is a cool-looking liquid metal.
This article discusses mercury exposure. Basically elemental mercury is fairly inert in the body, with only 0.01% of it absorbed by the digestive system. On the other hand, mercury vapor is much more toxic with 80% absorbed, so don't breathe hot mercury vapor. The toxic mercury in fatty fish has already been oxidized to methyl mercury or similar. Methyl mercury reacts with mercaptan groups (-SH) in proteins, and are bound in this way.

Amalgam fillings are 50% mercury with silver, tin and zinc. The mercury provides workability and durability to the mixture. I have not found foreign governments that ban amalgam fillings except in Scandinavia, but not because of exposure to patents or dentists, but because of concern about mercury in dental shop waste.

Bottom line is that I am not going to worry about getting my old fillings removed, and my mother-in-law should not either. On the other hand, I would probably want porcelain ones in the future -- out of an abundance of caution.