Background: Irrigation during endodontic therapy is required in order to remove debris, tissue remnants, microbes and smear layer. Sodium hypochlorite (NaOCl) and Chlorhexidine (CHX) are the most commonly used irrigants. Although they are reported to have good antimicrobial effects, both have limitations. Hence, a combination of NaOCl and CHX has been proposed to compensate for these limitations. However, this association forms a dense, orange-brown precipitate that stains walls of the pulp chamber. The aim of this study was to clarify in vitro if this precipitate affects the microleakage of endodontic sealers.
Material and Methods: Extracted human teeth were used for this study. The teeth were cut at the height of the cervix and instrumented with NiTi rotary instruments. They were then divided into 2 experimental groups. In the first group (Group A) irrigations were performed with 2ml NaOCl 1%, 1ml EDTA 17% and 1ml CHX 0.2% and in the second (Group B) with 2ml NaOCl and 2ml CHX. Following this, they were obturated with gutta-percha and roth sealer. The microleakage was determined using a fluid filtration method. The measurements were repeated a month later. All analyses were performed using Fisher exact test.
Results: Microleakage of Group A was lower than microleakage of Group B but the difference was not statistically significant.
Conclusion: The precipitate that is formed by NaOCl and CHX did not affect microleakage of endodontic sealers.
1. Athanassiadis B, Abbott PV, Walsh LJ. The use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics. Aust Dent J, 2007; 52(1):64-82.
2. Krishnamurthy S, Shashikala S. Evaluation and Prevention of the Precipitate Formed on Interaction between Sodium Hypochlorite and Chlorhexidine. J Endod, 2010; 36:1154-1157
3. Bui TB, Baumgartner JC, Mitchell JC. Evaluation of the interaction between Sodium Hypochlorite and Chlorhexidine Gluconate and its Effect on Root Dentin.
4. Spångberg L, Pascon EA. The importance of material preparation for the expression of cytotoxicity during in vitro evaluation of biomaterials. J Endod, 1988; 14:247-250.
5. Delany GM, Patterson SS, Miller CH, Newton CW. The effect of chlorhexidine gluconate irrigation on the canal flora of freshly extracted necrotic teeth. Oral Surg, 1982; 53:518-522.
6. Vivacqua-Gomes N, Ferraz CC, Gomes BP, Zaia AA, Teixeira FB, Souza-Filho FJ. Influence of irrigants on the coronal microleakage of laterally condensed gutta-percha root fillings. Int Endod J, 2002; 35:791-795.
7. Basrani BR, Manek S, Sodhi RN, Fillery E, Manzur A. Interaction between Sodium Hypochlorite and Chlorhexidine Gluconate. J Endod, 2007; 33:966-969.
8. Akisue E, Tomita VS, Gavini G, Poli de Figueiro JA. Effect of the Combination of Sodium Hypochlorite and Chlorhexidine on Dentinal Permeability and Scanning Electron Microscopy Precipitate Observation. J Endod, 2010; 36:847-850.
9. White RR, Hays GL, Janer LR. Residual antimicrobial activity after canal irrigation with chlorhexidine. J Endod, 1997; 23:229-231.
10. Kuruvilla JR, Kamath MP. Antimicrobial activity of 2.5% sodium hypochlorite and 0.2% chlorhexidine gluconate separately and combined, as endodontic irrigants. J Endod, 1998; 24:472-476.
11. Basrani B, Santos JM, Tjaderhane L, et al. Substantive antimicrobial activity in chlorhexidine-treated human root dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2002; 94:240-245.
12. Oncag O, Hosgor M, Hilmioglu S, Zekioglu O, Eronat C, Burhanoglu D. Comparison of antibacterial and toxic effects of various root canal irrigants. Int Endod J, 2003; 36:423-432.
13. Rosenthal S, Spangberg L, Safavi K. Chlorexidine substantivity in root canal dentin. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2004; 98:488-492.
14. Okino LA, Siquera EL, Santos M, Bombana AC, Fingueiredo JA. Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel. Int Endod J, 2004; 37:38-41.
15. Thomas JE, Sem DS. An In Vitro Spectroscopic Analysis to Determine Whether Para-Chloroaniline is Produced from Mixing Sodium Hypochlorite and Chlorhexidine. J Endod, 2010; 36:315-317.
16. Vianna ME, Gomes BP. Efficacy of sodium hypochlorite combined with chlorhexidine against Enterococcus faecalis in vitro. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2009; 107:585-589.
17. Marchesan MA, Pasternak Junior B, Afonso MM, Sousa-Neto MD, Paschoalato C. Chemical analysis of the flocculate formed by the association of sodium hypochlorite and chlorhexidine. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2007; May103(5):e103-105.
18. Chabra RS, Huff JE, Haseman JK, Elwell MR, Peters AC. Carcinogenicity of parachloroalinine in rats and mice. Food Chem Toxicol, 1991; 29:119-124.
19. Basrani BS, Manek S, Fillery E. Using diazotization to characterize the effect of heat or sodium hypochlorite on 2.0% chlorhexidine. J Endod, 2009; 35:1296-1299.
20. Cobankara FK, Adanr N, Belli S. Evaluation of the influence of smear layer on the apical and coronal sealing ability of two sealers. J Endod, 2004; 30:406-409.
21. Nowicki JB, Sem DS. An in vitro spectroscopic analysis to determine the chemical composition of the precipitate formed by mixing sodium hypochlorite and chlorhexidine. J Endod, 2011; 37:983-988.
22. Beard RR, Noe JT. Aromatic nitro and amino compounds. In: Patty’s Industrial Hygiene and Toxicology. 1981; pp 2413-2489.