Bridges are typically used to replace a single missing tooth. Although they can be used to replace more than one tooth, it will be up to the dentist to decide if the surrounding teeth and bone are going to be a good support system for new teeth. Bridges are basically crowns on either side of a missing tooth and a fake tooth in the middle. All three teeth are attached together and are cemented in the mouth. New technology and materials are making bridges stronger and more esthetic than in the past.