A root canal is sequentially cleaned in sections from the crown to the apex. An opening is first formed into the tooth to provide access into the root canal. The opening is preferably rectified to remove obstructions from fully accessing the anatomical root canal. The pulp material is then sequentially...http://www.google.ca/patents/US6042375?utm_source=gb-gplus-sharePatent US6042375 - Endodontic systems for progressively, sectionally and anatomically preparing root canals with specific instruments for each section having predetermined working lengths
