Crowns
What is a crown?
Crowns are an ideal restoration for teeth, which have been broken, or have been weakened by decay or a very large filling. The crown fits right over the remaining part of the tooth, making it strong and giving it the shape and contour of a natural tooth. crowns are sometimes also known as 'caps'.
Why would I need a crown?
There are a number of reasons. For instance:
- the tooth may have been weakened by having a very large filling.
- you may have discoloured fillings and would like to improve the appearance of the tooth.
- you may have had a root filling which will require a crown to protect it.
- you may have had an accident and damaged the tooth.
- it may help hold a bridge or denture firmly in place.
What are crowns made of?
Crowns are made of a variety of materials, and new materials are continually being introduced. Here are some of the options available at present:
- Porcelain bonded to preciou5 metal: This is what the majority of crowns are made from. A precious metal base is made and porcelain is then applied in layers over it.
- Porcelain: These crowns are not as strong as bonded crowns but they can look very natural and are most often used for front teeth.
- Porcelain and composite: Porcelain and composite resin materials can sometimes look the most natural. However, these crowns are not as strong as bonded metal crowns.
- Glass:These crowns look very natural and are used on both front and back teeth.
- Precious metal (gold and palladium): These crowns are very strong and hard-wearing, but are usually used at the back of the mouth, where they are not visible.
How is a tooth prepared for a crown?
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'. The amount of the tooth removed will be the same as the thickness of the crown to be fitted. Once the tooth is shaped, the dentist will take an impression of the prepared tooth, one of the opposite jaw and possibly another to mark the way you bite together. The impressions will be given to the technician, along with any other information needed to make the crown.
Are there any alternatives to post crowns for root-filled teeth?
If a root-filled tooth is not completely broken down, it may be possible to build it up again using filling material. This 'core' is then prepared in the same way as a natural tooth and the impressions are taken.
How long will a crown last?
The life of a crown will depend on how well it is looked after. The crown itself cannot decay, but decay Ian start where the edge of the crown joins the tooth. It is very important to keep this area as clean as your other teeth, or decay may occur which could endanger the crown. Properly cared for crowns will last for many years - your dentist will be able to advise you how long.
How are crowns fixed to teeth?
Once the fit and appearance o_ the crown has been checked - and approved by you - it will be cemented in place with special dental cement. The cement also forms a seal to help hold it firmly in place.
Will the crown feel different?
Because the shape of the crown will be slightly different from the shape of your tooth before it was crowned, you may be somewhat aware of it to begin with. Within a few days it should feel fine, and you will become unaware of it. The crown may need some adjustment if it feels proud of the surrounding teeth. If it is at all uncomfortable you should ask your dentist to check and adjust it.