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Interactions between irrigants commonly used in endodontic practice: a chemical analysis
Maíra Prado1, Helvécio M Santos Júnior, Claudia M Rezende
1Department of Restorative Dentistry, Endodontics Division, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
Journal of Endodontics
|March 26, 2013
Summary
Mixing common endodontic irrigants like sodium hypochlorite (NaOCl) and chlorhexidine (CHX) can form precipitates. Rinsing with distilled water may help reduce harmful by-product formation during endodontic treatment.
Area of Science:
- Endodontic chemistry
- Dental materials science
- Analytical chemistry
Background:
- Common endodontic irrigants include sodium hypochlorite (NaOCl) and chlorhexidine (CHX).
- Understanding interactions between irrigants is crucial for safe and effective endodontic procedures.
- Previous studies have not fully characterized the by-products of irrigant associations.
Purpose of the Study:
- To characterize by-products formed from associations of common endodontic irrigants.
- To investigate reactions between NaOCl and CHX with other irrigants like EDTA, citric acid, and phosphoric acid.
- To identify conditions that lead to precipitate formation.
Main Methods:
- Electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS) was employed.
- Various concentrations of NaOCl were associated with CHX (solution and gel), EDTA, citric acid, phosphoric acid, saline, ethanol, and distilled water.
- CHX was also associated with other irrigants, and solutions were mixed in a 1:1 ratio.
Main Results:
- CHX and NaOCl formed orange-brown precipitates (1-5.25% NaOCl) or orange-white precipitates (0.16% NaOCl).
- CHX reacted with EDTA to form a white precipitate, and with saline/ethanol to form salt precipitates.
- No precipitation occurred between CHX and citric acid, phosphoric acid, or distilled water. NaOCl with EDTA, citric acid, or phosphoric acid produced chlorine gas.
Conclusions:
- NaOCl causes chlorination of CHX, leading to precipitate formation.
- CHX reactions with EDTA, saline, and ethanol involve acid-base reactions, salting-out, and solubility effects.
- Intermediate distilled water rinses can minimize by-product formation during endodontic treatment.
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