Comparison of the In Vivo Antimicrobial Effectiveness of Sodium Hypochlorite and Chlorhexidine Used as Root Canal Irrigants: A Molecular Microbiology Study

By Rôças IN, Siqueira JF Jr

Date: 07/2012
Journal: JOE


Purpose: To compare the antimicrobial effects of 2.5% sodium hypochlorite (NaOCl) and 0.12% chlorhexidine digluconate (CHX) when used as irrigants during treatment of teeth with apical periodontitis


n: 47 single rooted/canal teeth with necrotic pulp and asymptomatic apical periodontitis

Inclusion & Exclusion:

were stated Bacterial samples were taken at baseline S1 (filing with #15 k using saline only), after chemomechanical preparation with NaOC S2L n: 30, and after chemomechanical preparation with 0.12% CHX S2 n: 17. Using PCR and reverse capture checkboard DNA-DNA hybridization


-S1 yielded positive PCR results for bacteria.

-In the 2.5% NaOCl group 40% were PCR negative for bacterial presence.

-In the CHX group 47% had a negative PCR results for bacteria.

-No significant difference was observed when comparing the incidence of negative PCR results in S2 samples from NaOCl and CHX groups

-Significant difference in the bacterial presence between S1 and S2 of both groups (NaOCL and CHX).


Using either NaOCl or CHX as the irrigant significantly reduced the number of bacterial taxa and their levels in infected root canals, with no significant difference between these 2 irrigants.

Combining NaOCL and CHX is recommended to benefit from the substantivity of CHX to dentin and organic matter dissolution from NaOCL.