Crowns are synthetic caps, usually made of a material like porcelain, placed over a tooth. Crowns are typically used to restore a tooth's function and appearance following a restorative procedure such as a root canal. When decay in a tooth has become so advanced that large portions of the tooth must be removed, crowns are often used to restore the tooth.
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 also serve an aesthetic use, and are applied when a discolored or stained tooth needs to be restored to its natural appearance.
With proper care, a good quality crown could last up to eight years or longer. 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.