Root canal treatment actually involves a series of visits to prepare the tooth, remove the tooth’s pulp (pulpectomy) and then finish the restoration, which usually involves the placement of an artificial crown. For minor cases of pulp damage, the entire process may be completed in one appointment. If there are no complications (such as severe infection or an existing artificial crown), the pulpectomy is performed during the first dental appointment.

Of this series of appointments, it is the pulpectomy itself that is often referred to as the root canal treatment. The pulpectomy may involve the following steps:

• X-rays can be taken immediately before the root canal procedure to show the location of root canals (there may be multiple canals), whether tissue infection exists in and around the tooth and if nerve endings are nearby.
  
  
• A local anesthetic may be administered to numb the nerves in and around the tooth. Nitrous oxide gas may also be used on some patients to help reduce anxiety. Those who have difficulty sitting still during a dental procedure – children, those with severe anxiety or mental illness or physical disabilities – may need a general anesthetic.
  
  
• A rubber sheet called a dental dam is placed over the affected tooth to keep it isolated and free of saliva and to keep debris from falling down the throat. A suction tube is placed into the mouth to dry up excess saliva.
  
  
• A hole is drilled into the tooth to reveal the pulp chamber. In molars and bicuspids, the hole is usually drilled through the top (crown) of the tooth. In incisors, the hole is usually drilled through the interior side of front teeth.
  
  
• The pulp is removed. Chemicals (e.g., sodium hypochlorite, hydrogen peroxide) and dental instruments (e.g., root canal files and reamers) are used to clean dead and infected tissue from the inner tooth. The root canals are enlarged and shaped using a series of thin files that increase in width as the canal is opened. Medication (antibiotics) may be placed into the site to eliminate bacteria.
  
  
• A temporary filling is usually placed into the crown to protect the drilled area from infection and saliva. In some cases, the dentist may leave the tooth open to drain for a few days.

Patients who feel pain or discomfort during the procedure are urged to notify the physician immediately. This may be an indication that the anesthetic is wearing off. The dentist or endodontist may recommend a signal (such as holding up a finger or hand) to indicate when there is pain.