What is a crown?
What is a crown?
A crown is a very strong precision fit cover that is placed over the tooth to strengthen it and protect it in the bite. Teeth become compromised, weak and prone to painful breakage when they contain more filling than original tooth structure, are cracked or are very worn and broken down due to decay or toothwear. If the tooth does break, it is not always possible to save it.
Placing a crown can be a way to preserve the tooth so that it is retained for life. The end result is that it looks perfectly like a tooth, and is matched to the other teeth. It is made in the laboratory by a specialist ceramist, who spends a lot of time making sure that it is perfectly matched, so that it cannot be detected in the smile.
Brittle root treated molar and top premolar teeth are crowned, to give them the best chance of being kept for a long time to come.
The preparation of the tooth takes 1 hour with the dentist, where impressions are taken and sent to the technician. A temporary crown is placed over the tooth and two weeks later the crown is ready for fitting, in a 45 minute appointment. Crowns have a 5 year manufacturer's warranty against fracture, however this is contingent on attending six monthly preventive care appointments, to ensure that the gum and bone support around the teeth is optimal, and early changes are detected and attended to. Failure to floss or brush correctly around a crowned tooth, or attend to six monthly preventive dental care can be detrimental to the longevity of a crown.
A crown can be placed over a tooth that is still alive (vital) or one that has been root treated (non-vital). Research indicates that for every tooth that is judged to be alive (vital) and crowned, that 10% go on to require root canal therapy. This is because the tooth is compromised to begin with, often with a deep filling or crack through it already, which may have compromised the pulp of the tooth.The dentist will take an x-ray in order to determine if the root of the tooth is healthy, and examine the tooth closely once all the old filling is removed. On occasions, a tooth that is cracked or very heavily filled, may require root canal therapy prior to crowning to ensure that an abscess does not develop, however this depends on the exact presentation of the tooth.