Root canal treatment is the process of cleaning and disinfecting the pulp chambers and canals of a tooth when there has been injury or damage to the pulp (nerve and blood vessels) of the tooth. This can result from deep decay that infects the pulp with bacteria or trauma that damages the tooth and pulp irreversibly. Sometimes the decay does not directly enter the pulp but if the restoration is very close to the nerve, this can cause irreversible damage that leads to the need for a root canal. If a tooth is abscessed where the infection is stemming from the pulp, a root canal is needed to cure the infection and save the tooth. Endodontic treatment involves anesthetizing the tooth, accessing (drilling) through the top of the tooth into the pulp chamber to find the canals. Then small files are used to clean out the canals and a strong bactericidal irrigant is used to disinfect. Once the canals have been cleaned and shaped with the various files, they are filled up with a rubber material called gutta percha. Once the root canal is completed, the top of the tooth is restored with a filling and then ideally a crown is placed on the tooth to prevent fracture.