When events occur that ultimately require a tooth being removed, a bridge is usually one option considered for its replacement. Also on the option list is an implant. Prior to the development of implants, bridges were the primary method of replacing missing teeth. They still are commonly used, especially if there are sturdy teeth on either side of the missing tooth space, or when an individuals health concerns preclude the use of an implant. These adjacent teeth are used as anchors for a permanently cemented or bonded false tooth. Anchor teeth are called abutments, and they are often covered by crowns or sometimes more conservative attachments like bonded ceramic fillings. A dental lab makes most bridges as one solid piece, so a bridge to replace one missing tooth with crown anchors would look like three crowns in a row with the center one being solid. A different analogy would be a central marble with two thimbles attached on opposite sides. Because crowns are so frequently used in this procedure, one reason a bridge might be selected over another option would be if both the anchor teeth would benefit from having crowns. This usually occurs when these teeth have large fillings already.
Bridges traditionally have been made with two layers, a foundation layer of cast metal for strength and a covering layer of porcelain for a natural appearance. Although rigid and strong, these have the disadvantages of not always looking as natural as the nearby teeth, making the gumline area of the tooth appear dark (especially if the gums have receded slightly), chipping or fracturing of the porcelain layer, and biocompatibility issues with toxic metals sometimes used in the foundation, such as beryllium or palladium.
Today we have advanced ceramic options which enable us to make strong bridges that contain no metal and are highly biocompatible. They also offer a more natural appearance and do not cause the dark gumline of the metal bridges.
The technique for making a bridge first involves the dentist reshaping and reducing the size of the abutment teeth so the crowns can slide over them and have the same dimensions of the original tooth shape. A detailed mold is taken of the teeth and sent to the dental lab that will be making the bridge. The dental assistant then makes a custom acrylic resin temporary bridge, and this is worn while the lab is making the permanent bridge. At the second appointment, the temporary is removed, the permanent bridge is fitted over the abutment teeth, and the bite adjusted. Bridges are permanently bonded or glued to the abutment teeth using specially developed dental adhesives.