Comparison of Reciproc, Wave One, Protaper, and One Shape rotary instruments in reduction of bacterial load in root canals

Abstract

Aim: To compare the effectiveness of Reciproc, Wave One, Protaper, and One Shape rotary instru-ments in reduction of E. faecalis in root canals. Methodology: In this in-vitro study, after initial stages of canal enlargement and irrigation, a suspension containing Entrococcus faecalis was inoculated into the root canals of 84 extracted single-canal premolars. The samples (apart from two positive and two negative controls) were randomly assigned into four groups according to rotary instruments used: Reciproc, Wave One, One Shape, Protaper. Each group was then subdivided to two groups based on irrigating solutions of normal saline and NaOCl. After instrumentation, the root canals were filled with brain-heart infusion (BHI) broth. Finally bacterial colony forming units (CFU) were counted. Results: Reduction in number of bacterial colonies before and after instrumentation and irrigation was not significantly different in different rotary instru-ment systems (P=0.128, F=1.955). However, NaOCl was more effective in reduction of bacterial load compared to normal saline (P<0.001, F=15.528). Conclusions: All rotary instruments used in the study are effective in reduction of the bacterial load.