Crowns are caps that are placed on the top of a tooth. Crowns are often used to restore a tooth's function and appearance following a restorative procedure such as a root canal. Crowns are often used to restore the tooth, when the decay in a tooth has become so advanced that large portions of the tooth must be removed.

Crowns are also used to attach bridges, cover implants, prevent a cracked tooth from becoming worse, or an existing filling is in jeopardy of becoming loose or dislocated. Crowns can also serve an aesthetic use when it is applied to discolored or stained tooth needs to be restored to its natural appearance. 

A tooth usually must be reduced in size in order to place the crown. A cast is made of the existing tooth and an impression is made. The impression is sent to the lab, which manufactures a custom-designed crown. In certain cases, a temporary crown is applied until the permanent crown is ready. Permanent crowns are then cemented in place.