Abstract

Microorganisms and their products play an important role in the pathogenesis of pulpal and periradicular diseases, so their elimination from root canal system as well as reinfection prevention are the main purpose of root canal treatment. This study was designed to compare the in-vitro efficiency of the Hero and M-Two rotary instruments in intracanal bacterial reduction. Fifty six human extracted teeth were divided into two equal experimental groups (n=25), Hero file as group 1 and M-Two file as group 2, and one control group (n=6). All samples were prepared by K-file No 20 and Gates Glidden No 2 and 3 before sterilization. The teeth were autoclaved and then were infected withEnterococcus faecalis. The experimental groups were instrumented either with Hero 4% or with M-Two files up to #30. To determine the level of remaining organisms, bacteria samples were collected after instrumentation. In the group 1, two samples and in the group 2, 12 samples represented complete elimination of bacteria. There was statistically significant difference between the two groups regarding the level of bacteria elimination (p<0/05). So using M-Two instrumentation technique reduces the intracanal bacteria more efficiently than Hero 4% instrumentation technique.

Key words: Enterococcus faecalis bacteria, Hero rotary file, root canal preparation, M-Two rotary file