A Comparison of One Shape and ProTaper Next Rotary Systems for Elimination of Enterococcus Faecalis from Root Canal: Microbiological and SEM Evaluation

Incomplete removal of micro- organisms from infected root canals is a common cause of failed endodontic treatment. The difficulty in eradication of Enterococcus faecalis from root canals plays an essential role in pathogenesis of persistent pulpal and periradicular infections. The aim of the present study was to compare the reduction of Enterococcus faecalis in root canals by mechanical instrumentation using two rotary systems (One Shape and ProTaper Next) and Hand K-file instrumentation by using microbiological and Scanning Electron Microscopy (SEM) evaluation. Fifty one freshly extracted mandibular premolars with a single root were collected. After pre-instrumentation sampling, they were divided into three groups, Group A, Group B and Group C in which biomechanical preparation was done using Hand K-File, OneShape and Protaper Next respectively. Reduction in pre- instrumentation and post- instrumentation values of Enterococcus faecalis were analysed using microbiological and SEM evaluation. Statistical analysis by paired ‘t’ test and p value showed that there was highly statistical significant difference in CFU count reduction between the pre-instrumentation and post-instrumentation values in all the groups (p<0.001). Statistical analysis by Kruskal-Wallis Test and Mann-Whitney Test showed that at 1mm and 3mm level, Group A (Hand K-File) scored significantly higher value followed by Group B (OneShape Apical) and Group C (ProTaper Next). The most effective instrumentation technique in eliminating Enterococcus faecalis from the root canal was ProTaper Next system in comparison to OneShape Apical and Hand K-File.