amalgams

An amalgam is an alloy that contains mercury as one of its principal constituents. The term derives from the Latin amalgama, meaning a softening or clinging together of metals with mercury. Mercury’s tendency to wet many metals makes amalgamation a useful way to produce intimate metal mixtures at room temperature. Amalgams occur in many historical and modern contexts, but dental and mining applications are the best known today.

Dental amalgam is the most widespread contemporary example. It is made by mixing mercury with other metals, typically silver, tin, copper, and small amounts of other elements. The resulting paste is placed in a prepared cavity and hardens over time into a durable restoration. Modern formulations reduce free mercury release and improve corrosion resistance, though concerns about mercury exposure remain a consideration in dental practice and public health.

Beyond dentistry, amalgamation is used in metallurgy to extract metals from ores, especially gold and silver. In gold mining, mercury forms an amalgam with gold, which is later heated to recover the metal and drive off mercury. In chemistry, elemental amalgams such as sodium amalgam or potassium amalgam serve as strong reducing agents and reagents.

Health, environmental, and regulatory issues center on mercury’s toxicity. Mercury can enter the body through inhalation or ingestion and can bioaccumulate. Safe handling, proper disposal, and regulatory controls mitigate risk. Ongoing research seeks alternative materials and safer processes, but amalgams remain in use where appropriate.