Root Canal Treatment (also called Endodontics) is required when the pulp inside your tooth becomes inflamed or infected through tooth decay, bacteria or damaged by an injury to your mouth which can lead to the pulp dying off. If the infection is left untreated, it can spread through the root canal system and form an abscess which can cause considerable pain, swelling and discomfort. In such situations, the options are either root canal treatment (RCT) or extraction. RCT is the preferred option in order to save the tooth (provided the tooth has a good prognosis otherwise). Usually, two or more appointments are required for an RCT, however, some cases can be completed in one visit depending on the level of infection, which tooth is being treated in relation to how many canals it has and ability to access, size and shape of the roots and whether the tooth has been previously root treated.