This is the most common endodontic treatment. The pulp tissue may become diseased from decay, a fracture, or trauma. When the pulp of the tooth has become diseased, the goal of the root canal treatment is to remove the diseased tissue from within the tooth. Once the diseased tissue is removed, a root canal filling is placed to seal the inside of the tooth to maintain a healthy, disease-free tooth. A core buildup and crown are then placed in most cases.