What are crowns and when are they required?
Commonly referred to as a "cap", a crown is a dental restoration that covers the tooth. Crowns strengthen and protect the tooth and are also used to improve the appearance of your teeth.
A crown may be advised in the following situations:
- The tooth has a very large filling such that the remaining tooth structure becomes weakened and can no longer support the filling.
- The tooth has been extensively damaged by caries.
- The tooth is fractured.
- The tooth is discolored.
- Root canal treated teeth tend to become brittle and are more apt to fracture and therefore need to be protected by a crown.
- When missing teeth are replaced with a (bridge), the adjacent teeth require crowns in order to support the replacement teeth.
What are the different types of crowns?
Crowns can be made from different materials. They include the full porcelain crown, the porcelain fused-to-metal crown and the all-metal crown. The type of crown to be selected depends upon the aesthetic concerns and the strength requirements of the teeth involved.
How are crowns made and fitted?
Fitting a crown requires at least two appointments.
The first visit
During your first visit, a local anesthetic is given after which the tooth is prepared for the crown. The decayed and weakened parts are removed and the tooth is repaired and shaped to receive the crown. Next, an impression or mold is made of the prepared tooth. The impression is sent to the laboratory and an exact model of the drilled tooth is made. The crown is then fabricated on this model.
Meanwhile, to protect the tooth a temporary plastic (acrylic) crown is placed over the prepared tooth. It prevents the drilled tooth from drifting its position and helps in keeping the gum around the tooth healthy.
The second visit
At this time, the temporary crown is removed and any temporary cement is cleaned from the prepared tooth. The final crown is tried onto the tooth and checked for accuracy in fit and in bite. Any discrepancies are adjusted and the crown is evaluated for aesthetics. If all these factors are acceptable, the crown is cemented permanently to the tooth.
How should I take care of the temporary crown?
The health of your gum tissue and the success of your final restoration depend upon your home care. Do not be afraid to clean your teeth between visits and avoid hard or sticky foods. Sometimes, even with meticulous care, temporary crowns or bridges may come loose. If this should occur, place the temporary crown or bridge back on your tooth immediately. Putting a drop of VaselineT or even toothpaste in the temporary crown or bridge will help hold it in place until you can schedule an appointment. Replacing the temporary crown immediately is very important as it only takes a short time for teeth to move. This may even necessitate new impressions resulting in a great deal of wasted time, energy and money.