Abstract
Incomplete removal of micro- organisms from infected root canals is a common cause of failed endodontic treatment. The difficulty in eradication of <i>Enterococcus faecalis</i> 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 <i>Enterococcus faecalis</i> 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 <i>Enterococcus faecalis</i> 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 <i>Enterococcus faecalis</i> from the root canal was ProTaper Next system in comparison to OneShape Apical and Hand K-File.
Highlights
Micro-organisms play an essential role in pathogenesis of pulpal and periradicular diseases and are an important factor affecting the results of endodontic treatment
The observations above showed that all instrumentation techniques appreciably reduce the bacterial count in the root canals
The results of the present study revealed, that the mean percentage reduction of E. faecalis after instrumentation in Group A (Hand K-File) was 95.51%, Group B (OneShape Apical) 97.74% and Group C (ProTaper ) 98.13%
Summary
Micro-organisms play an essential role in pathogenesis of pulpal and periradicular diseases and are an important factor affecting the results of endodontic treatment. Amongst the diverse bacteria species found in endodontic infections, Enterococcus faecalis stands out for its ability to grow in the presence or absence of oxygen, penetrate deep into dentinal tubules and survive adverse environmental conditions such as extreme alkaline pH, high temperatures and scarce nutrition. Pinheiro S L et al [1] reported that Enterococcus faecalis is the most frequent species found in persistent endodontic infections with a prevalence of 90% and is nine times more likely to be isolated from root-filled teeth than from primary infections. Its inherent resistance to intracanal disinfecting agents, adaptability to the harsh environmental stresses and ability to form biofilms within the root canals makes it the primary organism associated with post-treatment failure and association with persistent apical periodontitis, which makes it focus of research. Mechanical instrumentation is the core method for bacterial reduction during endodontic treatment of infected root canals. Bystrom A and Sundqvist G [2] demonstrated that mechanical instrumentation with a non-antimicrobial irrigant reduces the intracanal bacterial count enough to detect a quantifiable difference using appropriate sampling techniques
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
