Crowns are a type of dental restoration which, when cemented into place, covers the entire portion of the tooth that lies above the gum line. Since dental crowns encase the entire visible aspect of a tooth, a dental crown in effect becomes the tooth's new outer surface.
Crowns are used to rebuild broken or decayed teeth, to strengthen teeth, and to enhance the cosmetic appearance of teeth. Crowns can be made out of porcelain/ceramic, gold alloy, or a combination of both. Dental crowns are often referred to as "dental caps".