What is an silver colored filling?

Amalgam is a mixture of metals that includes mercury. For more than 150 years, amalgam has been used to restore decayed teeth because it is relatively inexpensive and durable, and it sets hard quickly in the oral cavity. Amalgam is more than 50% mercury, which is a known neurotoxin. Some studies suggest that exposure to mercury from amalgam over a long period of time can cause health problems in some individuals. Other metals used in amalgam include silver, copper, and tin.