Improve the Appearance & Protect Teeth that are Chipped, Broken or Heavily Restored

What Is A Crown?

Like a cap for the tooth, a crown is a hollow shell made of porcelain (tooth coloured) and/or gold that has the same shape as your tooth on the outer surface. It is cemented or glued over your own tooth. The tooth if first prepared to ensure that there is enough tooth structure and a suitable shape for the crown to fit snugly over the top. An impression is taken and a temporary crown is placed for about 1 or 2 weeks, after which a permanent crown is put in place. A crown is an investment, and will last more than 10 years.

Why Do I Need A Crown?

Crowns are used:

• To restore strength to heavily filled teeth when a filling is no longer viable.
• To prevent further cracks and chips in a weakened tooth.
• After Root Canal Treatment when there may be very little tooth structure remaining and to seal the root canals, in order to reduce re-infection by up to 60%.
• To improve the appearance of the tooth by masking any colour deformities.
• To perfect your smile, by straightening crooked or misshapen teeth
• To restore function so that you can chew food normally.
• To improve the lifespan of the tooth, making it highly resistant to further decay or damage.

A crown required to save and strengthen a tooth, with nerve exposure following an accident (Case 1) Trauma, decay or root canal treatment may severely weaken a tooth. A crown will fit over the existing tooth and replace the crown i.e the part of the tooth you can see above your gums.
Crowns on lower anterior teeth (Case 2) Crowns were placed on this patient's lower front three teeth, due to discolouration and malformation, creating a more desirable smile.

Types of Crowns

There are two types of crowns. A full crown covers the whole tooth, whereas a ¾ crown covers almost all of a tooth. Crowns strengthen weakened teeth and generally look as natural as your own dentition. The colour of the crown can not be altered once it has been made by the Dental Technician, thus before choosing to have a new crown it is recommended that you consider tooth whitening - as this will allow the practitioner to match the crown with your new whitened smile.

What Are Crowns Made Of?

The decision on which material is best to use when making a crown, is dependent on several factors, and requires an individual case assessment, by a skilled practitioner. After consultation with your dentist, you will be advised of your different clinical options.

Crowns for front teeth are generally made of:

• Tooth coloured material (such as porcelain) as used with the Cerec system
• Porcelain with a metal backing (such as gold)
• Completely metal (such as gold or stainless steel) which is frequently used on back teeth
• Acrylic plastic material

Some back teeth may need full gold crowns.

How Long Will It Take?

Depending on the type of crown chosen, you will need one to three appointments.

Cerec System

There are some crowns that can be made in one visit. These crowns are made using a computer with the Cerec in-house milling technology. There are no temporary restoration. A digital picture of your prepared tooth, combined with computer technology, allows a crown to be made in one two hour appointment. The natural looking crown is then adjusted and cemented in just one appointment.

Cusp fracture, due to large amalgam filling, is replaced with a Cerec® Crown (Case 3)
A cusp fracture is a tooth fracture that causes the hill-type tooth projection (or 'cusp') to break off; and if neglected may lead to tooth loss or root canal treatment. Through the use of a Cerec® or Porcelain and Metal crown, the tooth is strengthened and bacteria is prevented from entering the tooth leading to the infection and eventual death of the nerve.

Crowns Made in the Laboratory

Crowns that are made in a laboratory require two or three appointments approximately 7 - 10 days apart. For one tooth the first appointment is usually 1½ to 2hours; whereby, the tooth is prepared to receive the crown, an impression is taken for the laboratory to use when making the crown and a temporary crown placed on the prepared tooth. At the 2 nd and 3 rd appointment the crown is checked and then cemented into place. The 2 nd and 3 rd appointment/s take 30 minutes each on the same day.

The following is a step-by-step outline of the procedure required to make a crown within the laboratory.

1. After preparation of the tooth, a cord may be placed around the tooth to outline the margins clearly to the technician
   
   Cord placed around tooth.
   
   
2. An impression is taken, using siloelastic material.
   
   Impression showing the detail on the occlusal (biting) surface of the top teeth - allows for the crown to assimilate naturally with surrounding teeth.
   
   
3. A temporary crown is made from the impression, by the Dentist.
   
   Temporary crown made from impression .
   
   
4. Shade selection is made by the Dentist, so that the colour of the crown that is made by the Dental Technician will blend naturally with your smile.
   
   
   
5. Permanent crown on the anterior teeth naturally beautifies the smile.