Metal
Background
Metals were long used as bases for dentures, with the most popular metals being gold, aluminum, silver, tin, or some metallic alloy composed of multiple metals and including the aforementioned ones. (11) (13) (12) Among their advantages over vulcanite, metal bases tended to be stronger, thinner, and more durable. Where vulcanite was a poor conductors of heat, metal dentures were not and therefore avoided issues related to weakened mouth tissues. (13) However, dentures with metal bases were also more expensive and were not an economical choice for many patients. (1)
Construction
Furthermore, metal base plates were created by a process called swaging, in which denture plates were stamped and bended into shape through the use of dies and counter-dies. (6) A “die” is a facsimile of the mouth, specifically a copy of the plaster model in metal (zinc in most cases). A counter-die is a copy of the impression and is therefore a reversed image of the plaster model/die. (9) (13) The dies and counter dies were used in conjunction with a hammer to shape the mental plates into the correct form so that they were attachable to teeth and were compatible the patient’s mouth. (9)
