If the amalgam restoration is corroded, then:
Amalgam is a mixture of two or several metals, one of which is mercury, silver, tin, copper, and others. When powder alloy and liquid mercury are mixed, a chemical reaction occurs that produces dental amalgam in the form of a hard restoration material with a silver-gray color. Amalgam can be solid or liquid depending on the amount of mercury used. Amalgam is generally used to fill cavities. The use of amalgam as a material for filling teeth has been used since the beginning of the 20th century.
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