Crowns or “caps” replace parts of decayed teeth above the gum line. They fit over what is left of a tooth and act as its new outer surface. Crowns are made in a variety of materials including porcelain, metal with a thin ceramic layer, and even gold, which is used more commonly for teeth in the back of the mouth. Crowns act as healthy teeth, but they may come loose over time. If this happens, they may need to be re-cemented or replaced.
Crowns may be used to:
- repair teeth that have become too broken or decayed to be fixed with a filling
- cover teeth that have had the top parts removed due to severe damage
- repair broken or faulty fillings
- improve the appearance of a tooth
- seal a tooth after a root canal treatment
The process for placing a crown often takes two or more visits to the dentist. On the first appointment, the dentist will numb the area, first placing a jelly-like substance and then injecting an anesthetic. Sometimes a dentist will use nitrous oxide, or “laughing” gas, in order to help the patient relax and reduce the pain.
The dentist may also place a sheet of rubber with a metal frame inside the mouth to keep particles from being swallowed by the patient.
The dentist will then drill out and remove the tooth decay and create a mold out of an impression of the decayed tooth. This impression will allow a technician to create a crown that fits perfectly around the tooth. The dentist will then cover the decayed tooth with a temporary crown until the permanent crown has been created.
When it is ready, the dentist will prepare the patient’s tooth for the new crown. The dentist will start by again numbing the area in the same process used before. The temporary crown is then removed.
After the temporary crown is removed, the dentist will cement the permanent crown onto the damaged tooth, encasing it completely. They will then have the patient bite down on a piece of carbon paper to test the positioning of the crown. If it is not placed correctly, the dentist may reshape and polish the crown to make it fit perfectly.
After the treatment, a patient may experience numbness of the lips and gums until the anesthetic wears off after a few hours. If numbness occurs in a certain area, chewing should be avoided there to prevent injury.
In the event that the tooth decay is located near the pulp, a bride or implant may be more appropriate as a means of replacing the tooth entirely. If the pulp dies after a crown is placed, a root canal treatment may be necessary in order to remove it.