A fixed bridge allows a missing tooth or teeth to be cemented back into your mouth. The teeth on either side of the missing one(s) are prepared to receive crowns. Then a custom fitting bridge is fabricated in a dental laboratory. This one piece appliance is then cemented onto the adjacent teeth. Fixed bridges can be very esthetic and functional.
Most often these bridges are made of porcelain fused to gold to allow for nice esthetics. In the back of the mouth, for increased strength, all gold alloy can be used. For highly esthetic needs on front teeth a non metal all ceramic bridge can be made, although some strength is sacrificed.
Until the last few years, this was the state of the art method to replace a few missing teeth. They can be made quite quickly and they look great. If the adjacent teeth are already crowned or have large existing restorations a fixed bridge may still be the best choice. If the bone in the area of the missing tooth is deficient, making an implant more difficult, a fixed bridge would also be a good choice. Patients who take some medications (osteoporosis, some chemo therapies, etc) may also not be surgical candidates for implants making a fixed bridge a better choice.
The biggest disadvantage of the fixed bridge is that it involves the adjacent teeth. If down the road something happens to one of them (fracture, decay, etc) the whole project needs to be redone.