Today there are more choices for restorative materials than at any time in the past. Dental amalgam, also known as silver fillings, is one choice for teeth in the back of the mouth that has been in use for around 150 years. Amalgam is a metal alloy that contains silver, tin, copper, and mercury. Amalgam lasts a long time and is less expensive than other materials such as tooth-colored composites, porcelain, or gold.