Purpose: to compare the antimicrobial efficacy of 2.0% chlorhexidine and sodium hypochlorite as root canal irrigants.
N= 62 freshly extracted teeth.
•The surface of the extracted teeth were disinfected and access cavities prepared, the pulp was removed.
•the teeth were divided into three groups according to the irrigant used (2.0% chlorhexidine, 5.25% sodium hypochlorite and saline). the root canal system was instrumented using step-back technique. then the canals were filled with thioglycollate broth.
•The thioglycollate was cultured (post-irrigant culture).
•to evaluate substantivity, the canals were refilled with thioglycollate and incubated, then samples were obtained by paper points. (substantivity culture).
Most highlighted Results:
•both chlorhexidine and sodium hypochlorite significantly reduced the number of post irrigant positive cultures compared with saline.
•In both post irrigant and substantivity cultures, there was no significant difference in the reduction of the number of positive cultures between chlorhexidine and sodium hypochlorite.
•2% chlorhexidine is as effective as sodium hypochlorite as an antimicrobial endodontic irrigant with less toxicity. However it lacks tissue dissolving ability.
•NaOCL remains the irrigant of choice and chlorhexidine can be used as an alternative irrigant for patients allergic to NaOCL or with very patent apices.