Comparison of the effect of two endodontic irrigation protocols on the elimination of bacteria from root canal system: a prospective, randomized clinical trial

By Beus C, Safavi K, Stratton J, Kaufman B.

Date: 08/2013
Journal: JOE

Purpose: to compare the results of a nonactivated single-irrigation protocol (NAI) that used only 1% NaOCl with a passive ultrasonic multi-irrigation protocol (PUI) that used 1% NaOCl, 17% ethylenediaminetetraacetic acid, and 2% chlorhexidine in rendering canals bacteria free.

N= 50 teeth (49 patients)

Inclusion:  patients presenting to the endodontic clinic for primary root canal treatment of a posterior tooth with apical periodontitis


•4 bacterial samples were taken in the study:

(1) before instrumentation (1st visit) ,

(2) after instrumentation and irrigation (1st visit),

(3) after CaOH medication (2nd visit) and

(4) after final instrumentation (2nd visit)

•After disinfection and access, bacterial culture sample was collected

•After chemomechanical preparation (hand and rotary instruments) in a crown down technique, teeth were randomly divided into 2 groups based on the final irrigation protocol (passive ultrasonic and non activated)

•In both groups irrigation was performed gauge 27-mm needle  placed 1 mm from WL

•Activated file was size 15. After final irrigation, a 2nd bacterial sample was taken.

•CaOH was placed into the canals and teeth temporized

•In the 2nd visit (after≥7 d), CaOH removed and bacterial sample

•Any additional instrumentations were then completed and a final bacterial sample was obtained.

Most highlighted Results: 

After 1st visit, 80% of the samples in the conventional group and 84% of the ultrasonic group were bacteria-free. After CaOH medication, and after final instrumentation, the differences in the number of bacteria free samples between the 2 groups were not significant.

Clinical significance: 

the depth of needle penetration and total volume of irrigation are important in achieving negative cultures