1. A silver-white, naturally occurring isometric alloy of silver and mercury having a brilliant metallic luster.
2. Any alloy of mercury with another metal or other metals.

It has been used for more than 150 years in dental restorations; only gold has been used longer for this purpose.

It is known that a fraction of the mercury in amalgam is absorbed by the body and that people with amalgam restorations in their teeth have higher concentrations of mercury in various tissues (including the blood, urine, kidneys, and brain) than people without amalgam fillings.

In 1993, the Public Health Service of the U.S. Department of Health and Human Services published a report acknowledging that scientific data are insufficient to conclude that amalgam fillings have compromised health. Furthermore, there is no evidence that removal of amalgam fillings has a beneficial effect on one's health; however, there are others who claim that over time, there is serious health damage.

It was not until about 1980 that serious consideration was given to the possibility that mercury vapor escaping from amalgam fillings might be affecting health, specifically producing subtle effects on the central nervous system. Such effects have been reported among dentists and other dental personnel, whose exposures are well below industrial levels but above those from fillings alone.

Apparently, further studies will be needed to ascertain whether the combined exposure to the metals in dental amalgam may lower the threshold for adverse immunological reactions.

A retort (vessel where substances are distilled or decomposed by heat) in which mercury is distilled off from gold, or silver amalgam is obtained in amalgamation.

1. The treating of precious-metal ores with mercury for the purpose of extracting their values.
2. The mixing of mercury with another metal, or metals, to form an alloy.
3. The process of separating metal from ore by alloying the metal with mercury; formerly used for gold and silver recovery, where it has been superseded by the cyanide process.

A dental amalgam consisting of mercury and copper.

Unlike a silver and tin alloy, it is prepared a moment before use by heating the required quantity over a flame. The alloy then melts and remains plastic for a time, even at room temperature.

It set after insertion in the tooth cavity. Copper amalgam is said to have bactericidal properties.

A soft mixture of mercury and alloys of silver, tin, and copper that becomes very hard when set and has been used to fill tooth cavities; however, such application are being replaced with another plastic-type of filling.