General Dentistry: The Difference Between Crowns and Bridges

There are several dental treatments available to restore teeth that are severely damaged or missing altogether. Crowns and bridges are two examples of these treatments. The difference between the two of them can be difficult to understand because, while treatment with a bridge sometimes involves crowns, not every crown is a bridge. Knowing which of the two treatments is appropriate for which situation helps you determine which kind of treatment you need.

Crowns

In dentistry terms, a crown is a tooth-shaped cap that fits over an existing tooth. This strengthens a tooth that has been weakened by decay or other damage, restoring its original appearance and shape. Crowns can be made of either a metal alloy or a tooth-colored material, such as ceramic or acrylic. Some crowns are made of both, with the tooth-colored material covering the surface of the metal crown to combine the strength of the latter with the natural appearance of the former.

So that the crown fits in with the surrounding teeth and has the same appearance, the dentist takes an impression of the tooth which forms the basis of the crown. The tooth is prepared by drilling it down to a small peg to make room for the crown. When the crown is ready, it is sealed in place with an adhesive after being placed over the tooth for a snug fit. The length of time it takes to prepare the crown varies, but if it is more than a few hours, you will receive a temporary crown until the permanent one is ready.

Bridges

A bridge is a replacement for one or more missing teeth. Up to four adjacent teeth can be replaced with a single bridge. Once the treatment is complete, the bridge is fixed in place and cannot be removed. A bridge consists of one or more false teeth to replace those that are missing. This is a prosthesis called a pontic. The pontic is anchored in place to one or both of the healthy teeth on either side. The most common type of bridge uses two crowns on the healthy teeth adjacent to either side of the pontic to hold it in position. This requires alteration of the adjacent teeth as would be done to crown an unhealthy tooth.

There are also other methods of anchoring bridges in the mouth. A cantilever bridge requires that only one adjacent tooth be crowned, while a Maryland bridge is anchored by two metal wings that are bonded to the back of the adjacent teeth, requiring minimal alteration. However, these types of bridges can only go in certain areas of the mouth, while a traditional bridge can replace teeth anywhere.