Root canal treatments are designed to save a tooth that is infected or inflamed. During one or two appointments, the infected nerve is removed, the canal is disinfected, then filled with a rubbery material called gutta percha. Most teeth need a crown to protect them from breaking following a root canal treatment. There is a common misconception that root canal treatments can be painful - this a thing of the past. Modern medicine allows for the tooth to be fully anesthetized for a surprisingly smooth procedure.