Crowns
A crown is a tooth-shaped cover placed over a tooth that is badly damaged or decayed. A crown is made to look like your tooth. Many people call it a cap.
Crowns may be placed for several reasons. Usually, the tooth has been broken or damaged a great deal by decay. As a result, a filling can’t replace enough of the tooth or make the tooth strong enough. A crown may hold together parts of a cracked tooth. It also can be used to hold a bridge in place. Crowns can be used to improve appearance, as well. They may be placed to cover misshapen or badly discolored teeth.
Before placing a crown, your dentist may need to build up a foundation to support it. A foundation is needed if large areas of the tooth is decayed, damaged or missing.
Your dentist will also take an impression of the teeth above or below the tooth that will receive the crown. The purpose is to make sure the crown will fit into your normal bite.
The impressions are sent to the lab, where the crown is made. During that time, you will have a temporary crown placed. These crowns are usually made of plastic. They are made in advance by the laboratory or made by the dentist during your preparation visit. Then the dentist fits the temporary crown to your tooth.
These crowns are not meant to last for a long time. In some cases, however, a temporary crown can stay in place for a year or longer. If it needs to last longer, a lab-made plastic crown is best. It is stronger and will last longer than a temporary plastic crown that is made by the dentist.
Temporary cement is used to keep the crown in place. It is special cement that is designed to be weak. This allows your dentist to easily remove the temporary crown at each visit as your permanent crown is fitted.
At a second visit, your dentist will remove the temporary crown and test the permanent one. Sometimes crowns need additional polishing or glazing or some other adjustment before they are placed. Once the crown is ready, it’s cemented to your tooth.