A crown is an artificial cap made to cover a natural tooth. The term “crown” can refer to a natural crown (the part of a tooth that is visible in the mouth) or a dental restoration that covers the top part of the tooth. 

An artificial crown is a dental prosthesis that covers or replaces the natural crown of a tooth. It typically covers the entire natural crown, on all sides and chewing surfaces. Artificial crowns can be used to cover and strengthen teeth that have been damaged. They may be used to improve the appearance of a tooth that is oddly shaped, badly discolored, or not in proportion with the neighboring teeth. Crowns can be used in cavity restoration when the tooth decay is too widespread for a filling, to restore a broken or cracked tooth, or prevent a tooth from breaking.

Crowns are commonly used as the last step after root canal treatment. Teeth become brittle as a result of this treatment and a crown will prevent further damage to the tooth (e.g., fracture). In these cases, the pulp of the tooth is removed from the root canal and the canal is filled with material such as gutta percha. A post may be placed in the root canal if there is insufficient natural tooth to support a crown. A crown is then typically placed in the area. Crowns can also be used to support a bridge or cover an implant.

Other types of dental restorations include inlays and onlays. These restorations cover smaller portions of the tooth, such as only the top part of the chewing surface. Inlays cover the smallest portion and may be slightly larger than a filling, while onlays cover at least one cusp of a tooth. Because onlays cover the cusps of teeth they offer better structural support. Inlays and onlays are more conservative restorations than crowns because less tooth structure is drilled away to fit.

Multiple visits to a dental office are required to prepare, place and adjust a crown. The crown is constructed in a dental laboratory based on impressions taken by the dentist. The multiple visits and labor crowns require means they usually cost more than simpler restorations, such as fillings.