A crown is a cap that is placed over a tooth and held in place by dental adhesive or cement.
As a protective cover for badly decayed teeth or fractured teeth
To strengthen teeth with large fillings or protect teeth that have been root canal treated (particularly molars)
Occasionally to correct minor problems in natural teeth like spacing and irregular shape or severe discolouration.
Crowns can be made from a variety of materials. They can be made from plastic, ceramic or metal alloys. A combination of metal and ceramic is also possible to maximise strength and simulate the appearance of natural teeth.
Firstly, a thorough clinical check is carried out by your dentist to ensure the tooth is suitable. This involves taking an x-ray to ensure that the root is healthy and that the tooth is suitable for a crown.
Your dentist will be able to advise you on material choices, treatment sequence and any other concerns you may have.
The tooth to be crowned is then prepared. This involves trimming of the tooth size (usually under local anaesthesia) followed by an impression (mould) of the prepared tooth. This reduction is required to create space for the crown to be fitted. The mould taken is then sent to a laboratory where skilled technicians will fabricate the crown to fit your tooth perfectly. In the meantime, a temporary crown is made and fitted onto the trimmed tooth.
At the second appointment, the temporary crown is removed and the tooth surfaces cleaned. The completed crown is tried on the tooth for fit, harmony with the bite, and appearance. Finally, the crown is cemented onto the prepared tooth with dental cement.
Crowns are generally very strong, which is why we recommend them for strengthening weak teeth. However, the underlying tooth is still prone to decay and gum disease. The most vulnerable portion of the crown is the margin or the junction between tooth and crown.
To ensure your crown has the best life-span, daily brushing and flossing are essential, as well as a diet low in sugar.
Life-span very much depends on the underlying tooth and the how well your mouth is maintained. On average, they last around 10 years. Post-crowns (crowns supported off a peg on Root Canal Treated teeth) have a much shorted lifespan, often only up to 5 years.
Occasionally, Ceramic on the surface may chip or fracture. Avoid chewing excessively-hard substances like boiled sweets and bones.
Your dentist can advise you whether you are suitable and give you a rough guide as to how long its life-expectancy will be as each tooth is individual.