Crowns

What is a crown?

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’.

Why would I need a crown?

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 it
· it may help hold a bridge or denture firmly in place.

What is a crown made of?

Crowns can be made of a variety of different materials and new materials are continually being introduced. Some of the most popular options are listed below.

Porcelain bonded to precious metal: this is what most crowns are made from. A precious metal base is made and then porcelain is applied in layers over it.

Porcelain crowns: these crowns are made entirely out of porcelain and are not as strong as bonded crowns, but they can look very natural and are most often used for front teeth.

All-ceramic crowns: this modern technique offers a metal-free alternative, which can give the strength of a bonded crown and the appearance of a porcelain crown. Therefore it is suitable for use in all areas of the mouth.

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.

Gold alloy crowns: gold is one of the oldest filling materials. Today it is used with other metal alloys to increase its strength, which makes it a very hardwearing restoration. These crowns are white or gold in colour.

How is a crown prepared?

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.
Once the tooth is shaped, the dentist will take an impression (mould) of the prepared tooth, one of the opposite jaw and possibly another to mark the way you bite together.

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.

How is the crown fitted?

When the 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.

How long does the treatment take?

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. There will usually be about 1 to 2 weeks in between appointments.

Will the crown be noticeable?

No. The crown will be made to match your other teeth exactly. The shade of the neighbouring teeth will be recorded, to make sure that the colour looks natural and matches the surrounding teeth.

How long will the crown last?

Properly cared for crowns should last for many years. Your dentist will be able to tell you how long the crown may be expected to last.