Root canal treatment is usually carried out (also called endodontics) when the blood or nerve supply of the tooth (known as the pulp) is infected through decay or injury. You may not feel any pain in the early stages of the infection. In some cases, your tooth could darken in colour, which may mean that the nerve of the tooth has died (or is dying). If this occurred your tooth would need root canal treatment as the pulp has become infected and maybe dying. Left untreated the infection may spread through the root canal system of the tooth eventually leading to an abscess.
An abscess is an inflamed area in which pus collects and can cause swelling of the tissues around the tooth. The symptoms of an abscess can range from dull ache to severe pain and swelling. The tooth may also be very tender when you bite. Your dentist may need to prescribe you antibiotics to settle the infection prior to beginning root canal treatment. If root canal treatment (RCT) is not carried out, the infection will spread and the tooth may need to be taken out.
Root canal treatment it should feel no different to having an ordinary filling done. The aim of the treatment is to remove all infection from the root canal. The root is then cleaned and filled to prevent any further infection.