A root canal is a treatment of the pulp of the tooth that is inflamed, infected, or dead. The dental pulp is a soft substance in the center of the tooth that consists of the nerve, blood vessels, and connective tissue. The pulp chamber is the hollow part in the center of the tooth that contains the pulp, and it continues down canals that extend through the roots of teeth and into the surrounding bone. Some roots have more than one root canal, but all have at least one canal.