Crown and Bridge

crown is a restoration that covers a tooth and is made from porcelain or a combination of metal and porcelain. There are several reasons why a tooth may need a crown. The main reasons include 1) Extensive decay that leaves inadequate tooth structure to retain a conventional restoration. 2) Fracture of a cusp from a tooth that already has a large restoration. 3) Post root canal treatment. Studies have shown that teeth that are root canal treated, especially in the posterior part of the mouth, are extremely susceptible to fracture if not covered with a crown. This is due to the weakness of the remaining tooth, the tooth becoming more brittle because of the lack of fluid internally, and the large forces that are generated in the molar and premolar regions.

There are several steps in fabricating a crown. First, the tooth is prepared. During this process, approximately 1.5 mm is removed from the outside of the coronal portion of the tooth. This allows for adequate space for the materials of the crown.  A provisional or temporary crown is made at this time. This provisional will protect the tooth and provide proper esthetics and function. Next impressions are made. This will provide the lab a duplicate model of the prepared tooth on which the crown will be fabricated, as well as adjacent teeth and opposing teeth. The shade is also taken at this time, often utilizing digital photography, to insure that the new crown will match the existing teeth. When the crown is completed, it is tried in to verify fit, shade, contacts, and occlusion (bite) and if everything is correct it is cemented into place.

The final crown looks, acts, and feels like a natural tooth. When a tooth is lost and there are enough natural teeth remaining to support the missing one, a bridge is one of the options available to us to restore the missing tooth. The process is similar to a crown except that in this case the teeth adjacent to the missing one are prepared and the crowns are joined together with a pontic (or fake tooth). The teeth appear as three or more separate teeth.