Sometimes root canal therapy is needed when the nerve in the tooth is in the process of dying or is completely necrotic.  Teeth that have a “dead” or “dying” nerve in them can cause great pain because the next stage is a dental abscess.  A dental abscess can lead to loss of sleep, throbbing, pain to hot, fever, feeling of pain in the ear and even hospitalisation if left untreated for long enough.  Root canal therapy is the alternative to having a tooth extracted and simply means “removing the nerve” from the tooth.  This happens normally over 3 appointments and is done with local anaesthetic for comfort.  Not all teeth will have a good prognosis with root canal therapy and your dentist will discuss this with you.  Something to keep in mind when starting root canal therapy is that more often than not a crown is the treatment of choice as the final restoration to protect a tooth that has had root canal therapy.  This is an additional cost to be considered and your dentist will discuss this with you.