When the nerve of a tooth is affected by decay or infection, root canal therapy is needed. In order to save the tooth, the pulp (the living tissue inside the tooth), nerves, bacteria, and any decay are removed and the resulting space is filled with special, medicated, dental materials, which restore the tooth to its full function.
Having a root canal done on a tooth is the treatment of choice to save a tooth that otherwise would die and have to be removed. Many patients believe that removing a tooth that has problems is the solution, but what is not realized is that extracting (pulling) a tooth will ultimately be more costly and cause significant problems for adjacent teeth.
In rare cases, root canal therapy fails to work as expected. The treated tooth might not heal properly or a patient might experience post-surgical complications that jeopardize the tooth. Root canal re-treatment involves the removal of the previous crown and packing material, the cleansing of the root canals, and the re-packing and re-crowning of the tooth. In short, root canal re-treatment is almost identical to the original procedure, aside from the structural removal. The success rate for a root canal re-treatment runs at around 75%.