When the nerve of a tooth gets infected by deep caries or suffers a deteriorating process from traumatic bite or a fracture, it needs to be removed, and the canal(s) cleaned, disinfected and filled with gutta-percha and cement for posterior restoration. The purpose of a root canal treatment is to save the tooth eliminating the infection and protecting the decontaminated tooth from future bacterial invasion. Depending on the condition of the tooth due to caries, a fracture or the bone around it, a tooth may or may not be restorable.