Clean root canal systems are essential for successful endodontic treatment. With contributions from leading endodontists from around the world, Dr. Nestor Cohenca here presents the etiology of endodontic disease caused by the endodontic biofilm and all therapies available to predictably disinfect the root canal system, thus increasing successful endodontic outcomes. Disinfection of Root Canal Systems: The Treatment of Apical Periodontitis is an evidence-based manual that describes root canal anatomy, the endodontic biofilm, and the role of disinfection before presenting the most up-to-date methods of irrigation and disinfection. Individual chapters are devoted to each method, such as positive pressure irrigation, apical negative pressure irrigation, sonic activation, photodynamic therapy, laser technology, and ozonization and electrochemical activation. Clinical photographs throughout show proper irrigation and disinfection techniques.