This option is used to treat infection or irreversible inflammation of a tooth nerve (‘pulp’) by the removal of the pulp from the root canals of the tooth. When a tooth becomes infected (often as a result of a large cavity or deep filling), the nerve cannot be repaired by the body’s immune system. The infected nerve must be removed from the root canals, and the canals disinfected and sealed to clear the infection and prevent it from returning. Some dental infections cause toothache which may be very mild to very severe. However, many dental infections are pain free, and you may know nothing about an infection until your dentist spots the signs.