Abstract
Introduction
The purpose of this in vitro study was to determine whether para-chloroaniline (PCA) is formed through the reaction
of mixing sodium hypochlorite (NaOCl) and chlorhexidine (CHX).
Methods
Initially, commercially available samples of chlorhexidine acetate (CHXa) and PCA
were analyzed with 1H nuclear magnetic resonance (NMR) spectroscopy. Two solutions, NaOCl and CHXa, were
warmed to 37°C, and when mixed they produced a brown precipitate. This precipitate
was separated in half, and pure PCA was added to 1 of the samples for comparison before
they were each analyzed with 1H NMR spectroscopy.
Results
The peaks in the 1H NMR spectra of CHXa and PCA were assigned to specific protons of the molecules,
and the location of the aromatic peaks in the PCA spectrum defined the PCA doublet
region. Although the spectrum of the precipitate alone resulted in a complex combination
of peaks, on magnification there were no peaks in the PCA doublet region that were
intense enough to be quantified. In the spectrum of the precipitate to which PCA was
added, 2 peaks do appear in the PCA doublet region. Comparing this spectrum with that
of precipitate alone, the peaks in the PCA doublet region are not visible before the
addition of PCA.
Conclusions
On the basis of this in vitro study, the reaction mixture of NaOCl and CHXa does not produce PCA at any measurable
quantity, and further investigation is needed to determine the chemical composition
of the brown precipitate.
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 accessOne-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:
Subscribe to Journal of EndodonticsAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- In vitro antimicrobial activity of several concentrations of sodium hypochlorite and chlorhexidine gluconate in the elimination of Enterococcus faecalis.Int Endod J. 2001; 34: 424-428
- In vitro evaluation of the antimicrobial activity of chlorhexidine and sodium hypochlorite.Oral Surg Oral Med Oral Pathol Oral Radio Endod. 2004; 97: 79-84
- Sodium hypochlorite accident: inadvertent injection into the maxillary sinus.J Endod. 1993; 19: 180-182
- Complication in the use of sodium hypochlorite during endodontic therapy.Oral Surg Oral Med Oral Pathol. 1991; 71: 346-348
- Comparison of antibacterial and toxic effects of various root canal irrigants.Int Endod J. 2003; 36: 423-432
- In vivo antimicrobial activity of 2% chlorhexidine used as a root canal irrigating solution.J Endod. 1999; 25: 167-171
- A comparison of 2.0% chlorhexidine gluconate and 5.25% sodium hypochlorite as antimicrobial endodontic irrigants.J Endod. 1994; 20: 276-278
- Antibacterial activity of 2% chlorhexidine gluconate and 5.25% sodium hypochlorite in infected root canal: in vivo study.J Endod. 2004; 30: 84-87
- Chlorhexidine substantivity in root canal dentin.Oral Surg Oral Med Oral Pathol Oral Radio Endod. 2004; 98: 488-492
- Residual antimicrobial activity after canal irrigation with chlorhexidine.J Endod. 1997; 23: 229-231
- Antimicrobial substantivity of chlorhexidine-treated bovine root dentin.J Endod. 2000; 26: 315-317
- Antimicrobial activity of 2.5% sodium hypochlorite and 0.2% chlorhexidine gluconate separately and combined, as endodontic irrigants.J Endod. 1998; 24: 472-476
- Influence of irrigation regimens on the adherence of Enterococcus faecalis to root canal dentin.J Endod. 2008; 34: 850-854
- Evaluation of the interaction between sodium hypochlorite and chlorhexidine gluconate and its effect on root dentin.J Endod. 2008; 34: 181-185
- Interaction between sodium hypochlorite and chlorhexidine gluconate.J Endod. 2007; 33: 966-969
- International Agency for Research on cancer: IARC monography on the evaluation of carcinogenic risks to human. Lyon.France. 1997; 57: 38-39
- Toxicity of 4-chloraniline in early life stages of Zebrafish (Danio rerio): II—cytopathology and regeneration of liver and gills after prolonged exposure to waterborne 4 chloraniline.Arch Environ Contam Toxicol. 1999; 37: 85-102
- Organic structure analysis.Oxford University Press, New York1998 (23–48)
- Microbial degradation of disinfectants. A new chlorhexidine degradation intermediate (CHDI), CHDI-C, produced by Pseudomonas sp. strain No. A-3.J Health Sci. 2005; 51: 357-361
- Microbial degradation of disinfectants: two new aromatic degradation products of chlorhexidine, chlorhexidine aromatic degradation product (CHADP)-4 and CHADP-6, produced by Pseudomonas sp. strain No. A-3.J Health Sci. 2006; 52: 58-62
- Myeloperoxidase-catalyzed incorporation of amines into proteins: role of hypochlorous acid and dichloramines.Biochem. 1982; 21: 6299-6308
- Chlorination of endogenous amines by isolated neutrophils: ammonia- dependent bactericidal, cytotoxic, and cytolytic activities of the chloramines.J Biol Chem. 1984; 259: 10404-10413
- Reactions of sodium hypochlorite with some compounds having reactive methylene groups.Cell Mol Life Sci. 1979; 35: 299
Article info
Publication history
Published online: December 14, 2009
Identification
Copyright
© 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
