What Are Crowns and Why Are They Used?

By Catherine M. Fascilla, D.D.S.

A crown is a tooth-shaped “cap” that is cemented or bonded over a tooth completely covering the visible portion of the tooth at or above the gumline. Its purpose it to restore shape, size and function. It gives the tooth strength and improves its appearance.

Crowns are placed for many reasons. They may be used to hold together parts of a cracked tooth or used over a tooth that has been severely decayed, worn or broken. They are used on teeth that have very large fillings that need to be protected from breakage or teeth that have had root canals. They are often used for cosmetic reasons for the improvement of the shape, size or shade of a tooth or several teeth. They are also placed over dental implants or to support a bridge when one or more teeth are missing.

Crowns are made of various materials. They can be made of metal including stainless steel, gold or alloys. They may be fabricated from porcelain fused to metal or they may be entirely ceramic or resin.

There are temporary crowns and permanent crowns. Temporary crowns are made in the dental office and used as a temporary restoration until the permanent crown is constructed by the lab. They are made of acrylic, resin or stainless steel.

Stainless steel crowns are prefabricated and are also used for children whose baby teeth are severely decayed. Pediatric dentists also place stainless steel crowns to protect the teeth of children who are at a high risk of tooth decay especially when their age, behavior or medical conditions make good oral hygiene difficult.

Porcelain fused to metal (PFM) has long been the material of choice for its strength, fit and its superior esthetics when compared to all metal crowns. All ceramic crowns have been improving over the years. Because they are now as strong as a PFM crown, fit as well and are more natural looking, they are rapidly becoming the crown of choice. While dental labs are still fabricating most of the permanent crowns, the CAD/CAM system of digital impressions and milled crowns allow for fabrication in the dental office as you wait.