Comparisons among three supplementary irrigation techniques and a calcium hydroxide dressing for bacterial elimination after chemomechanical preparation using the self-adjusting file

• SAF instrumentation significantly decreased the number of colony forming units in the prepared root canals.
• EA irrigation and PUI were more effective than the CHX final rinse and Ca(OH)2.
• Further modifications in supplementary approaches are required to enhance disinfection.

IntroductionBacterial elimination from the root canal is the ultimate goal of endodontic treatment. Many supplementary systems and substances have been introduced to improve root canal disinfection. This study aimed to compare the effectiveness of sonic and ultrasonic-activated irrigation, a chlorhexidine (CHX) final rinse, and a calcium hydroxide [Ca(OH)2] dressing in eliminating bacteria after chemomechanical preparation of root canals using the self-adjusting file (SAF).MethodsEighty maxillary and mandibular premolars were inoculated with Enterococcus faecalis for 4 weeks, instrumented with SAF, and randomly distributed into four test groups (n = 15) according to the supplementary approach used for bacterial elimination: EndoActivator (EA) irrigation, passive ultrasonic irrigation (PUI), CHX final rinse, and Ca(OH)2 dressing. Two groups (n = 10) used as a positive and negative controls. Bacteriological samples were obtained from the canals before and after SAF preparation and after the supplementary approaches. The number of bacteria in each sample was determined by plate count.ResultsThe bacterial population significantly decreased after SAF preparation (P < 0.001). EA irrigation and PUI were significantly more effective than the CHX rinse and Ca(OH)2 dressing in decreasing bacterial colony-forming units (P < 0.05).ConclusionsEA irrigation and PUI after chemomechanical preparation using SAF were more effective than the CHX final rinse and Ca(OH)2 dressing in decreasing root canal infection.