American Medical Association Family Medical Guide - American Medical Association [796]
Fitting a tooth with a crown
A broken, cracked, or heavily filled tooth can be repaired with a crown. The remaining part of the tooth is reshaped to receive the crown. The crown, a hollow shell, is fitted over the old tooth and cemented on.
Bridges
If you have a gap of up to about four teeth, with healthy natural teeth on both sides of the gap, your dentist may recommend using an artificial tooth or teeth called a bridge to fill the gap (see below). A bridge helps prevent the remaining teeth from shifting or tilting out of place. The dentist will prepare the two natural teeth on either side of the gap for crowning. He or she then cements the two crowns to the prepared teeth. Enough of a gap should remain between the base of the bridge and the gum ridge to allow you to clean the area properly. Bridges at the front of the mouth are made of an alloy faced with porcelain; bridges at the back of the mouth are usually made of gold or less expensive alloys. Resin-bonded bridges are used when the two teeth on either side of the gap are healthy. Instead of filing these healthy teeth down, a bridge is made to fit around them and is cemented into place with a special glue. Putting in a bridge normally requires three or four visits to the dentist. If you have a bridge, see your dentist regularly to make sure it fits properly. If you have pain, sores, or bleeding in your mouth, see your dentist immediately.
Removing a Tooth
Although dentists try to save teeth whenever possible, they sometimes have to remove them. For example, a tooth may be too decayed or badly broken to be saved with a root canal or a crown, or it may be causing crowding or misalignment (see page 1106). A tooth may be loose because of advanced gum disease, or it may be preventing another tooth from emerging from the gum.
After removing a tooth
After a tooth has been removed, a blood clot usually forms in the empty tooth socket in the gum (top). In some cases, the blood clot breaks down, resulting in what is called a dry socket (center). Eventually, new bone grows into the empty socket and is covered by gum tissue (bottom).
Bridges
If a tooth is missing (left), the gap can be filled with an artificial tooth called a bridge. The two teeth on either side of the gap are reshaped to enable them to accept crowns and anchor the bridge (center). The crowns are cemented to the reshaped teeth, holding the bridge in place (right).
Before removing a tooth, the dentist usually uses a local anesthetic to numb the tooth and gum. A general anesthetic or a sedative may be used for young children, to remove badly impacted third molars (wisdom teeth), to remove several teeth at once, or for people who are extremely anxious. After a tooth has been removed, be careful not to dislodge the clot that forms in the wound. If the socket bleeds persistently, bite on a clean, tightly folded handkerchief or gauze pad to stop the bleeding. Keep the pad in place for half an hour by clenching your teeth. If the bleeding does not stop, see your dentist immediately.
Dentures
If several teeth are missing, a partial denture is required to replace them. A full denture replaces all of the natural teeth. Dentures are made of tough plastic or of metal and plastic combined.
On a partial denture, the baseplate (artificial gums) often has clasps that fit around the natural teeth to help keep the denture in place. Full lower dentures stay in place by resting on the gum ridge and full upper dentures by suction to the roof of the mouth.
Fitting a denture usually requires several visits to the dentist. During the first visit, the dentist takes impressions of the gums and evaluates the relationship between the upper