When a tooth has been damaged by decay or through an accident, rather than remove the tooth completely, it is possible to fit a cover — known as a crown or cap — over the remaining tooth. Under local anesthetic the tooth is reduced in size by the same thickness as the final crown, which will be cemented onto the tooth. An impression of your teeth and gums is then made and a temporary cap is fitted over the tooth until a permanent crown can be made. During your next visit, your dentist will remove the temporary cap and cement the crown onto your tooth.