A bridge (made of porcelain) is a restoration that replaces or spans the space where one or more teeth have been lost. Your appearance, dental health and the proper functioning of your mouth are all important reasons for wearing a bridge. A bridge helps maintain the natural shape of your face and may help support your lips and cheeks. The loss of a back tooth may cause your mouth to sink and your face to look older. More important, though, your dental health may suffer when teeth are not replaced. Teeth work together. When a tooth is lost, the nearby teeth may tilt toward the empty space, or the teeth in the opposite jaw may shift up or down toward the space. This can alter your bite and place unusual stress on both the teeth and tissues in your mouth.

In addition, due to the increased stress, the gum tissues and the bone that hold teeth in place can break down from the resulting gum disease. Teeth that have tipped are difficult to clean, making them more likely to decay. As a result, even more teeth may eventually be lost. Missing teeth also can affect the way you chew and speak. Chewing on one side only may cause stress in your mouth and jaw joints. You also need your teeth to speak properly, since they help you make many of the sounds needed in speech.

A porcelain bridge is commonly cemented to the natural teeth next to the space left by the missing teeth. An artificial tooth, called a pontic, replaces the lost natural tooth, and restores its function. A pontic is attached to a crown (restoration that covers a tooth). Crowns, which are cemented on adjacent prepared teeth, serve as retainers that support the bridge.

 
Teeth adjacent to the gap are prepared.

 
The custom-made bridge is fitted and adjusted.

 
After adjustments are made, the bridge is cemented into place

One way to replace a tooth is the Maryland bridge. This bridge technique was first developed at the University of Maryland, and this is where it gets the name.

A Maryland bridge consists of a metal framework with a porcelain tooth baked on to the front of the framework. The framework then ends up as a false tooth with two metal wings on the side. These metal wings are prepared to have a porous surface so that they can receive a bonding agent, and then the wings are bonded to the back sides of the teeth on either side of the missing tooth. The picture on the right shows how this looks.

There are two main esthetic problems with a Maryland bridge, and both of them have to do with the use of the metal. The first problem is that natural teeth are translucent. Therefore, the metal backing that is bonded onto the back side of the front teeth will cause those teeth to darken slightly, and they will no longer match the color of the other front teeth. If the dentist doesn't take this darkening into account (and very few dentists do), the false tooth that is replaced will also be slightly lighter in shade than these darkened teeth on either side. The second problem is that the false tooth is a porcelain fused to metal tooth, and it lacks the natural translucency and vitality of your other teeth. The most esthetic false teeth are those made entirely with tooth-colored materials. An alternative is an Encore Bridge, which is made entirely of tooth-colored materials, and so it is more esthetic.