If a tooth has severe tooth decay or if you have a dental infection, a root canal is sometimes needed. A root canal is done with local anesthetic. We clean out where the pulp and nerve of a tooth are and fill it with a dental material called gutta percha. We discuss beforehand what type of restoration you will need to restore the tooth after treatment is completed. After a root canal, depending on whether it was a front tooth or back molar a dental crown will be needed or a filling material.