Effect of sodium hypochlorite, chlorhexidin and EDTA on dentin microhardness

  • Diyar Khalid Bakr Department of conservative, college of dentistry, Hawler Medical University, Erbil, Iraq.
  • Sazan Sherdil Saleem Department of P.O.P, college of dentistry, Hawler Medical University, Erbil, Iraq.
  • Basam Kareem Amin Department of conservative, college of dentistry, Hawler Medical University, Erbil, Iraq.
Keywords: Microhardness, EDTA, Chlorhexidine gluconate, sodium hypochlorite


Background and objective: The use of chemical irrigants solution in root canal therapy is capable of altering the proportion of organic and inorganic components of root canals. The structural properties of dentin may be changed such as permeability, solubility and microhardness. The aim of this study was to evaluate the effects of root canal irrigants on the microhardness of root canal by using three types of irrigant solutions with different concentration and normal saline used as control group. Methods: Root halves were prepared by longitudinal splitting of the roots of 56 freshly extracted caries free maxillary second premolars and embedded in autopolymerizing acrylic resin, leaving the dentin surface exposed. The root halves were randomly divided to seven groups composed of 16 samples each and treated for five minutes with one of the following irrigants: normal saline (control group), 0.2 % chlorhexidin, 2% chlorhexidin, 2.5% sodium hypochlorite, 5.25%, 5% Ethylene dimetha tetra hydrate EDTA and 17% EDTA. After surface treatment, the dentin microhardness of the root samples were recorded at the mid-root level by using a vicker microhardness tester. The data were statistically analyzed by using one-way analysis of variance, followed by Duncans test with a significant difference test at P ≤0.05. Results: EDTA, sodium hypochlorite, and 2% chlorhexidin significantly decreased the microhardness of root dentin compared with controls (P <0.05), while 0.2% chlorhexidin had no significant effect on the microhardness of root dentin. Conclusion: The irrigant solutions affect the microhardness of the samples except 0.2%.


West JD, Roane JB. Cleaning and shaping the root canal system. In: Cohen S, Burns RC, eds. Pathways of the Pulp, 7th ed. St Louis: CV Mosby; 1998. P. 203–57.

Aslantas EE, Buzoglu HD, Altundasar E, Serper A. Effect of EDTA, Sodium Hypochlorite, and Chlorhexidine Gluconate with or without Surface Modifiers on Dentin Microhardness. J Endod 2014; 40 (6):876-9.

Jeansonne MJ, White RR. A comparison of 2.0% of chlorhexidine gluconate and 5.25% sodium hypochloride as antimicrobial endodontic irrigants. J Endod 1994; 20:276-8.

Hulsmann M, Heckendorff M, Lennon A. Chelating agents in root canal treatment: mode of action and indications for their use. Int Endod J 2003; 36:810-30.

Panighi M, G’Sell C. Influence of calcium concentration on the dentine wettability by an adhesive. J Biomed Mater Res 1992; 26:1081-9.

Cruz-Filho AM, Sousa-Neto MD, Savioli RN. Effect of chelating solutions on the microhardness of root canal lumen dentin. J Endod 2011; 37:358–62.

Akcay I, Sen BH. The effect of surfactant addition to EDTA on microhardness of root dentin. J Endod 2012; 38:704-7.

Arends J, Bosch JJ. Demineralization and remineralization evaluation techniques. J Dent Res 1992; 71:924-8.

Panighi M, G’Sell C. Influence of calcium concentration on the dentine wettability by an adhesive. J Biomed Mater Res 1992; 26:1081-9.

Kandil HE, Labib AH, Alhadainy HA. Effect of different irrigant solutions on microhardness and smear layer removal of root canal dentin. Tan Dent J 2014; 11(1):1-11.

Akcay I, Sen BH. The Effect of Surfactant Addition to EDTA on Microhardness of Root Dentin. J Enodod 2012; 38 (5):704-7.

AL-Ashou WO. The Effects of Two Root Canal Irrigants and Different Instruments on Dentin Microhardness ( In Vitro Study). Al – Rafidain Dent J 2011; 1(1):63-70.

Saleh AA and Etman WM. Effect of endodontic irrigant solutions on microhardness of root canals dentine. J Dent 1999; 27:43-8.

Sousa SMG, Silva TL. Demineralization effect of EDTA, EGTA, CDTA and citric acid on root dentin: a comparative study. Braz Oral Res 2005; 19:188-92.

Khedmat S, Shokouhinejad N. Comparison of the efficacy of three chelating agents in smear layer removal. J Endod 2008; 34:599-602.

Dasilva LA, Sanguino AC, Rocha CT, Leonardo MR, Silva RA. Scanning electron microscopic preliminary study of the efficacy of smear clear and EDTAfor smear layer removal after root canal instrumentation in permanent teeth. J Endod 2008; 34:1541-4.

Zhang K, Kim YK, Cadenaro M. Effects of different exposure times and concentrations of sodium hypochlorite/ethylenediaminetetraacetic acid on the structural integrity of mineralized dentin. J Endod 2010; 36:105-9.

Slutzky- Goldberg I, Maree M, Liberman R, Heling I. Effect of Sodium Hypoch-lorite on Dentin Microhardness J Endod. 2004; 30:880-2.

Ari H, Erdemir A, Belli S. Evaluation of the Effect of Endodontic Irrigation So-lution on the Microhardness and Rough-ness of Root Canal Dentin. J Endod 2004; 30:792-7.

Oliveira L, Carvahlo C, Nunes W, Valera M, Camargo C, Jorge A. Effect of Chlorhexidin and Sodium Hypochlorite of Root Canal Dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007; 104:125-33.

How to Cite
Bakr, D., Saleem, S., & Amin, B. (2016). Effect of sodium hypochlorite, chlorhexidin and EDTA on dentin microhardness. Zanco Journal of Medical Sciences (Zanco J Med Sci), 20(1), 1175_1179. https://doi.org/10.15218/zjms.2016.0006
Original Articles