Inside every tooth is something called the pulp, which simply consists of a nerve, blood vessels, and connective tissue. If a large cavity, deep filling, crack or trauma compromise the pulp it will become inflamed, infected and likely painful. A root canal is a procedure that removes and cleans the pulp inside a tooth. A root canal is a procedure to save a tooth that would otherwise have to be extracted.
Root canal treatment success is dependent on sealing the tooth and supporting your remaining tooth structure shortly after the root canal is completed. This is achieved with both a permanent filling/post and crown. A crown is particularly important on a back tooth to prevent fracture of the root canal treated tooth and to also create a seal to protect the root canal from re-infection.