Crowns are a type of dental restoration which, often referred to as a “cap”, when cemented into place, fully covers that portion of a tooth which lies at and above the gum line. In comparison, composite fillings/inlays/onlays are dental restorations that are used to fill in or cover over just a portion of a tooth. 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 as a means by which to enhance the cosmetic appearance of teeth. It is prepared by your dentist, and requires more than one visit to complete.
A crown can be made of metal, porcelain, or porcelain bonded to metal. All-porcelain crowns look more like your natural teeth, and therefore are usually used for front teeth, while porcelain bonded to metal is stronger and better for crowns in the back of the mouth. Sometimes all-metal crowns are used for back teeth because of the metal’s strength.
To prepare your tooth for a crown, the tooth is first frozen with anesthesia, and then filed down so the cap can fit over it. An impression of the teeth and gums is made, and a temporary cap is fit over the tooth until the permanent crown is ready.
On your next visit, the dentist will remove the temporary cap and cement the crown onto the tooth. The crown will closely match the colour and shape of your natural teeth.