A crown is an artificial restoration that fits over the remaining part of a prepared tooth, making it strong and giving it the shape of a natural tooth. A crown is sometimes known as a ‘cap'.
Crowns are used to rebuild teeth that have been damaged through trauma or decay. They may be necessary in a number of situations:
Crowns can be made of a variety of different materials and new materials are being introduced all the time. Here are some of the most popular options: Porcelain bonded to precious or non-precious metal - A precious or non-precious metal base is made and then porcelain is applied in layers over it. This is the most commonly placed type of crown. All-ceramic crowns - Improvements in dental porcelains means that these crowns can be used for front and back teeth without the metal substructure. This gives superb aesthetics. Gold alloy crowns - Gold is one of the oldest filling materials and due to it's physical and chemical properties is still an excellent . Today it is used with other metals to increase its strength, which makes it a very hard-wearing restoration. These crowns are silver or gold in colour.
The dentist will prepare the tooth so it is the ideal shape for the crown. This will involve removing most of the outer surface, and leaving a strong inner core. The amount of the tooth removed will be the same as the thickness of the crown. Once the tooth is shaped, the dentist will take an impression (mould) of the prepared tooth, one of the other jaw, and possibly another to mark the way you bite together. They will then place a temporary crown on the tooth to protect it.
The impressions will be sent to a dental technician, along with details of the shade to use and other information needed for the crown to be made. 10 days - 2 weeks later the temporary is removed and the new crown is tried in. The fit, bite and appearance are checked carefully and if both you and your dentist is happy the crown is cemented. Sometime the crown needs to be adjusted and in some case has to be returned to the laboratory to remake it.