A crown is a circumferential support for a tooth which can no longer hold a filling. Most teeth which have had a root filling need a crown, as the tooth has lost its nutrients and blood supply by the root filling. The tooth turns into a brittle consistency which is hard, but can fracture if hit the wrong way.
The construction of a crown is very precise and generally requires at least two visits. During the first visit, the damaged tooth is prepared to accept the crown. It may be necessary to replace the damaged part of the tooth with a core first. An impression is taken and a temporary crown is sometimes put in place. At the second visit, the permanent crown is cemented onto the prepared tooth. If cosmetics are a concern, tooth coloured porcelain is baked onto the crown surface.
Many types of materials can be used to construct crowns, including porcelain, porcelain bonded to metal, gold and metal alloys. Many people have unexplained pain from filled back teeth, usually due to fine hair line cracks in the chewing part of the tooth. Placing crowns on these teeth relieves the pain and allows a return of full dental function for these teeth. In front teeth, older fillings can both weaken the teeth and cause “appearance” problems due to staining or chipping. In teeth with root canal fillings, crowns can prevent these teeth from breaking. Some of the indications for a crown are:
1. A previously filled tooth where there now exists more filling than tooth. The existing tooth structure becomes weakened and can no longer support the filling.
2. Extensive damage by decay.
3. Discolorations and compromised aesthetics.
5. Root canal treatment – After root canal treatment, teeth tend to become brittle and are more prone to fracture. They often need to be protected by a crown.
6. Bridges – When missing teeth are replaced with a bridge, the adjacent teeth sometimes require crowns in order to support the replacement teeth.
Crowns strengthen and protect the remaining tooth structure and can improve the appearance of your teeth.