Amalgam (silver) fillings have been used for decades and they remain one of the most commonly used filling materials. They are often referred to as metal fillings. Amalgam is a mixture of silver and other metals, such as copper, tin and zinc, grounded into powdered form. The silver powder is mixed with mercury and placed into the cavity preparation where it is shaped before hardening.
Lately, the safety of amalgam fillings has come under scrutiny because of the mercury it contains. The absorption of elemental mercury is known to be a contributing factor to several diseases, including Alzheimer's, multiple sclerosis, dementia and arthritis.
However, recent studies have proved amalgam fillings to be perfectly safe. It is true, that mercury vapor is toxic but mercury molecules in hardened amalgam are bound to the silver molecules rendering the level of toxicity harmless. The American Dental Association and the Food and Drug Administration have researched the safety of amalgam fillings and have found them to be not only safe but extremely effective.