What is a crown?
A crown is a hollow shell that covers or caps a specially prepared tooth. You may need a crown when an ordinary filling made of silver or amalgam, or a white plastic bonded filling cannot be used.
Crowns may be necessary for the following reasons;
» when a tooth has been damaged by decay leaving cusps unsupported or big portions missing
» when a large piece has broken off a heavily filled front or back tooth
» when a tooth has been badly damaged in an accident
» after root canal treatment when the remaining tooth would be vulnerable to chipping or cracking
» for cosmetic reasons, if there is staining from antiboiotic therapy as a child
» developmental defects in teeth
» to reposition teeth in the arch to improve overall appearance and function
What does a crown do?
A crown restores the shape and size of a tooth in the dental arch.
When done in porcelain, which is tooth coloured, it also restores the appearance of the tooth. In the case of a heavily filled back tooth, it also holds the remaining tooth structure together, just like an iron band around a wooden barrel.
What is a crown made of?
Crowns in front teeth are generally made of all porcelain or porcelain bonded to a gold backing. The same materials can be used for back teeth.
However, metal such as gold can be used for back teeth where appearance is less important and has great durability.
What is a Bridge?
A bridge is a number of crowns joined together to close a gap left by a missing tooth which is cemented permanently into the mouth to act like normal teeth.
The teeth on either side of the missing tooth are prepared for a crown and a false tooth is attached to them. It is usually made of porcelain bonded to gold for strength and aesthetics. It can also be all gold.
What is involved?
The missing part of the tooth may first have to be filled with one of the normal filling materials. The tooth is then reduced on the top and all sides until it looks like an elongated dome. An impression and other records are taken and a temporary crown fitted. The crown is constructed and tried in for fit and, where appropriate, colour.
Finally the crown or bridge is cemented into place.
Dr Michelle Lehmann has done a large volume of successful crown and bridgework in her practice. She specialises in restoring badly broken down teeth and can also correct the bite at the same time.
In her surgery, restoration can be done by one practitioner all the way through from root canal treatments, post and cores to the completion of simple or complex overlay of crown and bridgework.