Journal of AdvancedMedical and Dental Sciences Research

Background & Objectives: Shaping and cleaning of the root canals have a major role in reducing microorganisms. In this study, two different single file systems were evaluated for their efficiency in reducing E.faecalis from mesial root canals of extracted lower first molars quantitatively using bacterial culture method. The efficiency of 2% Chlorhexidine gel intracanal medicament was also evaluated, by placing them in the instrumented canals for 7 days. Method: 65 intact severely curved mesial root canals were selected using CBCT and divided into 5 groups (n=13). Samples in Groups I, II, III, and IV, were instrumented using One Shape, WaveOne, ProTaper, and Hand K files respectively as per manufacturer instructions and standardized irrigation protocol. Specimens were contaminated with E.faecalis for 21 days. Sample 1 confirmed the presence of organisms, Sample 2 showed a reduction in bacterialload after instrumentation. For Sample 3 specimens were divided into 2 subgroups. In subgroup 1, 2% Chlorhexidine gel was placed and in Subgroup 2, Tryptic soy agar nutrient was placed for 7 days. Results: Group I showed reduction in bacterial count by 70.13%, group II by 78.75%, group III by 74.7%, and group IV by 57.85%. In subgroup 1, statistically significant reduction in bacterial count was observed in group I only (p = 0.02). Conclusion: From the results obtained, WaveOne file in reciprocating motion showed the highest reduction in the bacterial count by 78.75%. 2% Chlorhexidine gel used as intracanal medicament for 7 days was not effective in reducing bacterial regrowth. Key words: OneShape, Wave One primary, 2% Chlorhexidine gel.