A decayed or broken tooth if left unattended, the bacteria gain entry to the live portion of the tooth called the pulp which contains the blood vessels and nerves. In due course of time this leads to an irreversible painful condition of the tooth which may require extraction of the tooth for pain relief RCT is the procedure by which only the irreparably damaged painful pulp is removed and the pulp space thoroughly cleaned, sterilised and filled. In effect the tooth is restored back to normal for the patient to chew with and smile.