When are they Necessary?

Crowns, and variations of crowns such as onlays, are designed to strengthen or reconstruct teeth that have extensive fillings or fractures. They may also be used to enhance the appearance of teeth.

• There are many materials used to construct crowns, from metals such as gold to resins and ceramics. Each material has its unique advantages and disadvantages. As a result, there is no “perfect” material.
• Most crowns today are constructed of a ceramic material fused to a metal substructure. These crowns have good aesthetics and great strength.
• Crowns for front teeth may be constructed of ceramic only, as the aesthetics have the edge over ceramic fused to metal. However, it is not always possible to use ceramic only crowns, especially in cases where there is very heavy pressure on the teeth.

How are Crowns Constructed?

The process of restoring a tooth with any type of crown takes a fairly similar course.

• Diagnosis: The tooth is evaluated to determine extent of decay, periodontal (gum) health, and type of crown restoration.
• Preparation: Local anaesthesia is administered and the tooth is prepared for the crown restoration.

• Impression: An impression (mould) is made of the tooth, as well as the adjacent teeth and the teeth of the other jaw. These impressions are used to construct models of the prepared tooth, and are used in the laboratory during fabrication of the crown
• Temporisation: A temporary crown is fabricated and placed on the prepared tooth for the duration of the laboratory phase. This is usually a number of weeks.