Why do amalgam (silver) fillings contain mercury?
Amalgam means a mix of metals. The filling material is made with a powder form of a few metals (silver, copper, tin, zinc) and a liquid form of mercury. The purpose of the mercury is to chemically bond to the other powdered metals causing a reaction which hardens the mixture into a solid metal to fill the tooth.. Mercury is the only metal that is liquid at room temperature, and the only chemical that can cause the hardening reaction for amalgam fillings. After the reaction is complete, no liquid mercury remains. The mercury becomes chemically bound and trapped in solid form.
