Amalgam is a commonly use dental filling that has been used for over 150 years. It is a mixture of mercury with at least one other metal. Currently, dental amalgams are composed of about 40% mercury, and 60% powder where the powder is made up of silver (~62%), tin (~26%), copper (~10%), and zinc (~2%). Amalgam has many advantages over other restorative material, such as low cost, strength, durability, and bacteriostatic effects. Its main disadvantages are poor aesthetics on anterior teeth and the known toxicity of mercury. Concerns about possible detrimental health effects from the low levels of mercury released from amalgam have resulted in a decline in the routine use of amalgam in recent years.