In PROSTHODONTIC or RESTORATIVE terms, a crown or cap is an artificial replacement of part or whole of the ANATOMICAL CROWN of a tooth. It restores ANATOMY, FUNCTION and usually AESTHETICS of the tooth, and is cemented or bonded to the remaining tooth substance.
Crowns are necessary when a tooth is generally broken down and fillings won't solve the problem. If a tooth is cracked, a crown holds the tooth together to seal the cracks so the damage doesn't get worse. Crowns are also used to support a large filling when there isn't enough of the tooth remaining, attach a bridge, protect weak teeth from fracturing, restore fractured teeth, or cover badly shaped or discoloured teeth.
Some crowns are made from full gold, where as others are made from an alloy of metals fused to a porcelain outer shell.
