The combination of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) results in the formation of a precipitate. In a previous study, we demonstrated the formation of 4-chloroaniline (PCA) in the precipitate by using x-ray photon spectroscopy (XPS) and time of flight secondary ion mass spectrometry (TOF-SIMS). The TOF-SIMS results showed a peak at 127 amu, which is characteristic of 4-chloroaniline. However, this could also be characteristic of other isomers of 4-chloroaniline such as 2-chloroaniline and 3-chloroaniline.
Aims and Methods
The aim of this study was to further identify the precipitate by using gas chromatography–mass spectrometry (GC-MS).
The results showed an absence of other aniline derivatives in the precipitate. Only PCA was found.
Further investigations of the precipitate should address the bioavailability of PCA leaching out from dentin and its cytotoxicity. Until the precipitate is studied further, it would appear prudent to minimize its formation by avoiding the use of CHX together with NaOCl.
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Published online: December 14, 2009
Accepted: October 26, 2009
Received in revised form: October 21, 2009
Received: September 25, 2009
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