Endodontics, or root canal therapy, is presented when a tooth has significant decay or damage, the tooth may be very painful because the nerve within the tooth is infected. In many cases it will be necessary to remove the nerve in order to treat the pain symptom. Root canal therapy involves cleaning and shaping each canal, and then filling them with a special inert material. Root canal therapy may also be necessary to save an otherwise non-restorable tooth that may need to be extracted. Once root canal therapy has been completed, the tooth should be restored as recommended.