Dental amalgam fillings have been using since the 19th century. They are quickly becoming obsolete and not usually recommended to restore cavities any more. Instead, composite fillings introduced in the 1960, are now in use.
Amalgam Fillings . One of the main problems with amalgam fillings is that it corrodes, releasing mercury vapor that can be absorbed into the body. In addition, the metal fillings will expand over time, putting unnecessary stress on the tooth structure. Eventually, the filling itself or the tooth structure may crack or fracture.