An amalgam filling is mostly recognized as a silver filling. Dental amalgam is a mixture of mercury,silver, tin, and cooper. Mercury, which makes up about 50 percent of the compound, is necessary to bind the metals together to provide a strong, hard, durable filling. Much concern over the safety of amalgams arises from the use of mercury as a bonding agent. But when mercury is combined with other materials in dental amalgam, its chemical nature changes, rendering it harmless.
Many dentist consider amalgam stronger than the resin-based composite, and therefore use amalgam for back teeth fillings, especially on primary teeth. Many patients prefer dental amalgam for the same reasons, plus its cost-effectiveness and ability to fill cavities quickly. It is estimated that more than 1 billion amalgam fillings are placed annually.
Deciding which type of filling to use is best made by the patient and dentist, taking into account the size and location of the cavity, patient history, cosmetic concerns, and cost. Ask your dentist to discuss all the choices available for dental fillings and help you decide which alternative is right for you.