Inconclusive results were reported about the cleaning and disinfection accomplished by the two irrigation methods .
There is insufficient evidence to cl aim general superiority of any one of these methods .
The aim of this study was to systematic ally review and critically analyse the published data on the treatment outcome ( primary outcome ) and on the  cleaning and disinfection of root canals  ( secondary outcomes ) achieved by negative pressure irrigation as compared to syringe irrigation .
Comparison of the effectiveness of three irrigation techniques in reducing intracanal Enterococcus faecalis populations: an in vitro study.
INTRODUCTION Several irrigation techniques have been recently introduced with the main objective of improving root canal disinfection . This in vitro study aim ed at comparing the intracanal bacterial reduction promoted by chemomechanical preparation with 3 different irrigation techniques . METHODS Root canals from extracted teeth were contaminated with Enterococcus faecalis ATCC 29212 for 7 days and then r and omly distributed into 3 experimental groups of 20 teeth each : group 1 , conventional irrigation with NaviTip needles inserted up to 3 mm short of the working length ; group 2 , same as group 1 , but supplemented with final irrigant activation by the EndoActivator system ; and group 3 , irrigation with the EndoVac system . NaOCl and ethylenediaminetetraacetic acid ( EDTA ) were the irrigants used in all experimental groups . The overall preparation time was kept constant for the groups , but the total volume ranged from 20 mL ( groups 1 and 2 ) to 43 mL ( group 3 ) . The control group was irrigated with saline solution ( total volume , 43 mL ) . Sample s taken before and after chemomechanical procedures were cultured , and the colony-forming units ( CFUs ) were counted . RESULTS Reduction in the bacterial population s was highly significant for all groups . The 3 experimental groups with NaOCl and EDTA as irrigants were significantly more effective than the control group with saline in reducing CFU counts . There were no significant differences between the 3 techniques tested . CONCLUSIONS There was no evident antibacterial superiority of any of the irrigation techniques evaluated in the present in vitro model
Inconclusive results were reported about the cleaning and disinfection accomplished by the two irrigation methods .
There is insufficient evidence to cl aim general superiority of any one of these methods .
The aim of this study was to systematic ally review and critically analyse the published data on the treatment outcome ( primary outcome ) and on the  cleaning and disinfection of root canals  ( secondary outcomes ) achieved by negative pressure irrigation as compared to syringe irrigation .