A bridge is used to close a gap in the mouth where a tooth is missing, in some cases it is not advisable to do an implant or denture to fill the gap.

This is done by preparing the two teeth on either side of the gap, like the dentist would if they where going to be crowned. A bridge is then made which is essentially two crowns joined together with a fake tooth in the middle. When the bridge is cemented it looks and functions like three new teeth, even though underneath there are only two teeth.