The effectiveness of Mtwo and step back instrumentation techniques on the elimination of enterococcus faecalis from root canal

The aim of this study was to compare the effect of Mtwo rotary system and step back hand system in reduction of enterococcus faecalis bacteria from the root canals of human extracted teeth.

In this study, 62 human extracted teeth were divided into two equal experimental groups with 23 teeth each and one control group two extra control groups with 5 teeth each as negative and positive were chosen for confirmation of the canal reinfection too. All of the samples were prepared by K Flie No 20 and Gates Glidden No 2 & 3 before sterilization. Then the teeth were autoclaved and reinfected with enterococcus faecalis. The experimental groups were instrumented either with Mtwo system or step back system. Bacteriological samples were taken after instrumentation to determine the amount of remaining bacteria.

In the group 1, fourteen samples and in the group 2, twelve samples represented complete reduction of bacteria. There was not statistically significant difference between two techniques (p>0.05)

Both Mtwo and step back systems are the same on reduction of the bacteria from root canal system, up to the same apical size.