A root canal therapy is necessary when the pulp which is located in the internal cavity of a tooth is infected usually due to caries or fracture/trauma which allows the entrance of bacteria. 

A tooth with infected pulp cannot heal by itself or with the use of any medications. Due the fact that the pulp among others is consisted of nerves that are connected with larger nerves with the brain, its inflammation is accompanied with severe pain, spontaneous or upon stimuli like cold, heat or pressure. The next stage of pulp inflammation –if the root canal necessary is not carried out- is pulp necrosis and inflammation of the periapical bone. The evolution of this infection if still left untreated is bone destruction, abscess and/or cyst formation. In any of the stages mentioned above the root canal therapy can eliminate symptoms like pain, prevent infection and bone destruction and save the natural tooth. 

During a root canal therapy the dentist creates an access cavity on the tooth, removes the pulp and disinfects the root canal system. The root canal system is then obturated with a special elastic material. The final step is the prosthetic restoration of the tooth. 

A root canal therapy is a common and safe dental procedure that saves natural teeth that would otherwise be lost.