In order to seal holes caused by tooth decay, amalgam has been and still is used by many dentists as a filler. Besides silver and various other metals, amalgam consists of 50 % mercury. In the body, mercury can be spread via the digestive tract to all areas of the body and be deposited in organs, bones, and the brain. The half-life period of mercury is 18 years.
Possible damage to health from amalgam is causing more and more people to have the harmful amalgam removed.