A root canal is the method used to repair and save a tooth that has become badly decayed and infected. Deep decay or tooth injury can cause the nerves tin the tooth to degenerate and the tissue to become infected. This infection can result in pain and serious health problems if not treated. A root canal procedure removes the dead nerve tissue from the canal and stops the infection from spreading. A crown is then used to permanently seal the tooth. The success rate of root canal therapy is extremely high and will allow you to save your tooth.