Crowns are artificial (prosthetic) teeth made of metal, porcelain or plastic. They are placed on remaining teeth to stabilize and preserve them. Full crowns cover the entire tooth, and partial crowns only cover part of the tooth. In order to create a well-fitting crown, the dentist first needs to file the remaining tooth and make a mold.
Bridges can replace one or several teeth, and are usually used for smaller gaps. They are only an option if there are enough remaining stable teeth, or if dental implants can be put in first. These are needed in order to keep the artificial teeth in place, so they can close the gap. The teeth that are used to support bridges are sometimes called "abutment teeth."
Different types of bridges may be needed, depending on the location and size of the gap. For example, a fixed bridge can be used to close a gap between two teeth. It is fixed to two abutment teeth – one on either side of the gap. These provide support for the bridge. Cantilever bridges are used to replace teeth that only have an abutment tooth on one side, such as a molar at the very back of your mouth. These kinds of bridges are supported by at least two teeth on the other side, for extra stability.
Bridges can be fixed in place in various ways. The abutment teeth can be recontoured (filed down and reshaped) and then fitted with crowns. The artificial tooth is then fixed to the crowns on either side, forming a bridge. In inlay bridges, fillings are put in the abutment teeth that the bridge is anchored to. Resin-bonded bridges (also called Maryland bridges) bond the artificial tooth to the backs of the neighboring teeth using short metal “wings.”