Root Canal Treatments also known as root canal therapy is a treatment offered when the tooth has decayed so far that the nerves inside the tooth are also affected. Usually the tooth is very painful and tender to touch. This is a sign of infection that has formed below the tooth. Root canal procedure involves cleaning out all the decay in the tooth and going into each root of the tooth where the nerves usually reside and cleaning them out. Once the canals are very clean and free from infection then an inert filling material is placed inside the canals and the tooth restored usually with a crown.