The Effect of Sodium Hypochlorite and Chlorhexidine as Irrigant Solutions for Root Canal Disinfection: A Systematic Review of Clinical Trials

Published:February 04, 2016DOI:


      • Of the 172 potential articles, only 4 randomized clinical trials and 1 nonrandomized clinical trial were included in this systematic review.
      • The laboratory methods used to evaluate root canal disinfection were heterogeneous among studies (culture techniques and molecular methods).
      • The 5 studies compared sodium hypochlorite and chlorhexidine by collecting samples from the root canal before and after the protocol treatments.
      • Randomization was conducted in 4 of the 5 studies.
      • There was a lack of agreement between the findings of the selected studies.



      This systematic review aimed to compare the effectiveness of sodium hypochlorite and chlorhexidine for root canal disinfection during root canal therapy.


      A literature search for clinical trials was made on the PubMed (MEDLINE), Web of Knowledge, SCOPUS, and Science Direct databases and in the reference lists of the identified articles up to January 2015. Quality assessment of the selected studies was performed according to the Consolidated Standards of Reporting Trials statement.


      One clinical trial and 4 randomized clinical trials were selected from the 172 articles initially identified. There was heterogeneity in the laboratory methods used to assess the root canal disinfection as well as in the concentrations of the irrigants used. Therefore, meta-analysis was not performed. Two studies reported effective and similar reductions in bacterial levels for both irrigants. Sodium hypochlorite was more effective than chlorhexidine in reducing microorganisms in 1 study, and another reported opposite findings. Both root irrigants were ineffective in eliminating endotoxins from necrotic pulp root canals in 1 study. Trial design and information regarding randomization procedures were not clearly described in the clinical trials. No study compared laboratory results with clinical outcomes.


      The available evidence on this topic is scarce, and the findings of studies were not consistent. Additional randomized clinical trials using clinical outcomes to compare the use of sodium hypochlorite and chlorhexidine during root canal therapy are needed.

      Key Words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of Endodontics
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Byström A.
        • Happonen R.P.
        • Sjögren U.
        • Sundqvist G.
        Healing of periapical lesions of pulpless teeth after endodontic treatment with controlled asepsis.
        Endod Dent Traumatol. 1987; 3: 58-65
        • Sjögren U.
        • Figdor D.
        • Persson S.
        • Sundqvist G.
        Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis.
        Int Endod J. 1997; 30: 297-306
        • Regan J.D.
        • Fleury A.A.
        Irrigants in non-surgical endodontic treatment.
        J Ir Dent Assoc. 2006; 52: 84-92
        • Zehnder M.
        Root canal irrigants.
        J Endod. 2006; 32: 389-398
        • D'Arcangelo C.
        • Varvara G.
        • Fazio P.D.
        An evaluation of the action of different root canal irrigants on facultative aerobic-anaerobic, obligate anaerobic, and microaerophilic bacteria.
        J Endod. 1999; 25: 351-353
        • Wong D.T.
        • Cheung G.S.
        Extension of bactericidal effect of sodium hypochlorite into dentinal tubules.
        J Endod. 2014; 40: 825-829
        • Rôças I.N.
        • Siqueira Jr., J.F.
        Identification of bacteria enduring endodontic treatment procedures by a combined reverse transcriptase-polymerase chain reaction and reverse-capture checkerboard approach.
        J Endod. 2010; 36: 45-52
        • Gordon T.M.
        • Damato D.
        • Christner P.
        Solvent effect of various dilutions of sodium hypochlorite on vital and necrotic tissue.
        J Endod. 1981; 7: 466-469
        • Zehnder M.
        • Kosicki D.
        • Luder H.
        • et al.
        Tissue dissolving capacity and antibacterial effect of buffered and unbuffered hypochlorite solutions.
        Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002; 94: 756-762
        • Gernhardt C.R.
        • Eppendorf K.
        • Kozlowski A.
        • Brandt M.
        Toxicity of concentrated sodium hypochlorite used as an endodontic irrigant.
        Int Endod J. 2004; 37: 272-280
        • de Sermeño F.
        • da Silva L.A.
        • Herrera H.
        • et al.
        Tissue damage after sodium hypochlorite extrusion during root canal treatment.
        Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009; 108: e46-e49
        • Ringel A.M.
        • Patterson S.S.
        • Newton C.W.
        • et al.
        In vivo evaluation of chlorhexidine gluconate solution and sodium hypochlorite solution as root canal irrigants.
        J Endod. 1982; 8: 200-204
        • Ferraz C.C.
        • Gomes B.P.
        • Zaia A.A.
        • et al.
        In vitro assessment of the antimicrobial action and mechanical ability of chlorhexidine gel as an endodontic irrigant.
        J Endod. 2001; 27: 452-455
        • Ohara P.
        • Torabinejad M.
        • Kettering J.D.
        Antibacterial effects of various endodontic irrigants on selected anaerobic bacteria.
        Endod Dent Traumatol. 1993; 9: 95-100
        • Siqueira Jr., J.F.
        • Batista M.M.
        • Fraga R.C.
        • de Uzeda M.
        Antibacterial effects of endodontic irrigants on black-pigmented gram-negative anaerobes and facultative bacteria.
        J Endod. 1998; 24: 414-416
        • Addy M.
        • Moran J.M.
        Clinical indications for the use of chemical adjuncts to plaque control: chlorhexidine formulations.
        Periodontol 2000. 1997; 15: 52-54
        • Gottumukkala S.N.
        • Sudarshan S.
        • Mantena S.R.
        Comparative evaluation of the efficacy of two controlled release devices: chlorhexidine chips and indigenous curcumin based collagen as local drug delivery systems.
        Contemp Clin Dent. 2014; 5: 175-181
        • Manthena S.
        • Ramesh A.
        • Srikanth A.
        • et al.
        Comparative evaluation of subgingivally delivered chlorhexidine varnish and chlorhexidine gel in reducing microbial count after mechanical periodontal therapy.
        J Basic Clin Pharm. 2015; 6: 24-28
        • Okino L.A.
        • Siqueira E.L.
        • Santos M.
        • et al.
        Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel.
        Int Endod J. 2004; 37: 38-41
        • Rôças I.N.
        • Siqueira Jr., J.F.
        Comparison of the in vivo antimicrobial effectiveness of sodium hypochlorite and chlorhexidine used as root canal irrigants: a molecular microbiology study.
        J Endod. 2011; 37: 143-150
        • Moher D.
        • Hopewell S.
        • Schulz K.F.
        • et al.
        CONSORT 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials.
        Int J Surg. 2012; 10: 28-55
        • Kuruvilla J.R.
        • Kamath P.
        Antimicrobial activity of 2.5% sodium hypochlorite and 0.2% chlorhexidine gluconate separately and combined, as endodontic irrigants.
        J Endod. 1998; 24: 472-476
        • Vianna M.E.
        • Horz H.P.
        • Gomes B.P.
        • Conrads G.
        Identification and quantification of archaea involved in primary endodontic infections.
        J Clin Microbiol. 2006; 44: 1274-1282
        • Gomes B.P.
        • Martinho F.C.
        • Vianna M.E.
        Comparison of 2.5% sodium hypochlorite and 2% chlorhexidine gel on oral bacterial lipopolysaccharide reduction from primarily infected root canal.
        J Endod. 2009; 35: 1350-1353
        • Ercan E.
        • Özekinci T.
        • Atakul F.
        • Kadri Gül
        Antibacterial activity of 2% chlorhexidine gluconate and 5.25% sodium hypochlorite in infected root canal: in vivo study.
        J Endod. 2004; 30: 84-87
        • Gu L.
        • Kim J.R.
        • Ling J.
        • et al.
        Review of contemporary irrigant agitation techniques and devices.
        J Endod. 2009; 35: 791-803
        • Byström A.
        • Sundqvist G.
        Bacteriologis evaluation of the effect of 0.5 percent sodium hypochlorite in endodontic therapy.
        Oral Surg Oral Med Oral Pathol. 1983; 55: 307-312
        • Byström A.
        • Sundqvist G.
        The antibacterial action of sodium hypochlorite and EDTA in 60 cases of endodontic therapy.
        Int Endod J. 1985; 18: 35-40
        • Siqueira Jr., J.F.
        • Rôças I.N.
        • Favieri A.
        • Lima K.C.
        Chemomechanical reduction of the bacterial population in the root canal after instrumentation and irrigation with 1%, 2.5%, and 5.25% sodium hypochlorite.
        J Endod. 2000; 26: 331-334
        • Alves F.R.
        • Almeida B.M.
        • Neves M.A.
        • et al.
        Time-dependent antibacterial effects of the self-adjusting file used with two sodium hypochlorite concentrations.
        J Endod. 2011; 37: 1451-1455
        • Naenni N.
        • Thoma K.
        • Zehnder M.
        Soft tissue dissolution capacity of currently used as potential endodontic irrigants.
        J Endod. 2004; 30: 785-787
        • Hulsmann M.
        • Hahn W.
        Complications during root canal-irrigation—literature review and case reports.
        Int Endod J. 2000; 33: 186-193
        • Yesilsoy C.
        • Whitaker E.
        • Cleveland D.
        • et al.
        Antimicrobial and toxic effects of established and potential root canal irrigants.
        J Endod. 1995; 21: 513-515
        • Rosenthal S.
        • Spangberg L.
        • Safavi K.
        Chlorhexidine substantivity in root canal dentin.
        Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004; 88: 488-492
        • Siqueira Jr., J.F.
        • Guimarães-Pinto T.
        • Rôças I.N.
        Effects of chemomechanical preparation with 2.5% sodium hypochlorite and intracanal medication with calcium hydroxide on cultivable bacteria in infected root canals.
        J Endod. 2007; 33: 800-805
        • Siqueira Jr., J.F.
        • Rôças I.N.
        Diversity of endodontic microbiota revisited.
        J Dent Res. 2009; 88: 969-981
        • Peters O.A.
        Current challenges and concepts in the preparation of root canal systems: a review.
        J Endod. 2004; 30: 559-567
        • Peters O.A.
        • Paque F.
        Root canal preparation of maxillary molars with the self-adjusting file: a micro-computed tomography study.
        J Endod. 2011; 37: 53-57
        • Rodrigues R.C.
        • Antunes H.S.
        • Neves M.A.
        • et al.
        Infection control in retreatment cases: in vivo antibacterial effects of two instrumentation systems.
        J Endod. 2015; 41: 1600-1605
        • Vera J.
        • Siqueira Jr., J.F.
        • Ricucci D.
        • et al.
        One versus two-visit endodontic treatment of teeth with apical periodontitis: a histobacteriologic study.
        J Endod. 2012; 38: 1040-1052
        • Ricucci D.
        • Loghin S.
        • Siqueira Jr., J.F.
        Exuberant biofilm infection in a lateral canal as the cause of short-term endodontic treatment failure: report of a case.
        J Endod. 2013; 39: 712-718
        • Siqueira Jr., J.F.
        • Rôças I.N.
        Polymerase chain reaction-based analysis of microorganisms associated with failed endodontic treatment.
        Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004; 97: 85-94
        • Sathorn C.
        • Parashos P.
        • Messer H.H.
        How useful is root canal culturing in predicting treatment outcome?.
        J Endod. 2007; 33: 220-225
        • Alves F.R.
        • Siqueira Jr., J.F.
        • Carmo F.L.
        • et al.
        Bacterial community profiling of cryogenically ground samples from the apical and coronal root segments of teeth with apical periodontitis.
        J Endod. 2009; 35: 486-492
        • Fedorowicz Z.
        • Nasser M.
        • Sequeira-Byron P.
        • et al.
        Irrigants for non-surgical root canal treatment in mature permanent teeth.
        Cochrane Database Syst Rev. 2012; 9 (review): 1-55