Crowns fit over a tooth, like a hat (or cap) fits on your head, to reinforce a weakened tooth. A crown is usually made of a material like porcelain and cemented into place.
Crowns are typically used to restore a tooth’s function and appearance following root canals or cuspal fractures, or to prevent further fracture of a weakened tooth. When decay in a tooth has become so advanced that large portions of the tooth must be removed, crowns are often required to restore the tooth.
Crowns are also used to attach bridges, cover implants, prevent a cracked tooth from becoming worse, or reinforce an existing filling is in jeopardy of becoming loose or dislocated. Crowns also serve an aesthetic use, and are applied when a discolored or stained tooth needs to be restored to its natural appearance.
A tooth must usually be reduced in size to accommodate a crown. An impression is made of the existing tooth and a cast is made. The impression is sent to a special lab, which manufactures a custom-designed crown. In some cases, a temporary crown is applied until the permanent crown is ready. Permanent crowns are cemented in place.
Crowns are sometimes confused with veneers, but they are quite different. Veneers are typically applied only to relatively small areas.
Caring For Your Crowns
With proper care, a good quality crown could last 7-10 years or longer. The longevity of your crown can depend on the quality of your dentist, the lab used and your care, as well as the state of the tooth before it was crowned. Just like bridges, it is rare that the crown itself breaks down; it is most often a cavity that develops farther down on the tooth due to difficulties in cleaning the area or recession exposing the weaker root surface to cavity-forming bacteria. It is very important to clean the area around the crown to avoid excess plaque or collection of debris around the restoration.
Certain behaviors such as jaw clenching or bruxism (teeth grinding) significantly shorten the life of a crown. Moreover, eating brittle foods, ice or hard candy can compromise the adhesion of the crown, or even damage the crown.