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'. A bonded crown is a crown with a metal base and porcelain coating.
Crowns are an ideal restoration for teeth that have been broken, or have been weakened by decay or a very large filling. A crown could be used for a number of other reasons, for instance:
- you may have discoloured fillings and would like to improve the appearance of the tooth.
- you may have had a root filling which will need a crown to protect what is left of the tooth.
- it may help hold a bridge or denture firmly in place.
The dentist will prepare the tooth to the ideal shape for the crown. This will involve removing most of the outer surface, and leaving a strong inner core.
Once the tooth is shaped, the dentist will take an impression (mould) of the prepared tooth.
The impressions will then be given to the dental technician, along with an appropriate shade and other information needed for the crown to be made.
In root-filled teeth it may be necessary to insert a post before placing a crown. A post provides support and helps the crown stay in place. A post can be made of prefabricated stainless steel which the dentist can fit directly into the root canal, or a custom-made post can be constructed by the dental technician to accurately fit the shape of the prepared root canal. The post is placed into the root canal and cemented in position, ready for the crown to be attached.
A temporary crown will be made so that you can use the tooth while you wait for the crown to be made. This crown may be more noticeable but is only a temporary measure.
When you and your dentist is happy with the fit and appearance of the new crown it will be fixed in place with special dental cement or adhesive. The cement forms a seal to hold the crown in place.
You will need to have at least two visits: the first for the preparation, impression, shade taking and fitting the temporary crown; and the second to fit the permanent crown.