Department of Endodontics, Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
J Endod. 2010 Feb;36(2):312-4. doi: 10.1016/j.joen.2009.10.031. Epub 2009 Dec 14.
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.
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.
次氯酸钠（NaOCl）和洗必泰（CHX）的组合会形成沉淀物。在之前的一项研究中，我们通过使用 X 射线光电子能谱（XPS）和飞行时间二次离子质谱（TOF-SIMS）证实了沉淀中形成了 4-氯苯胺（PCA）。TOF-SIMS 结果显示在 127 amu 处出现一个峰，这是 4-氯苯胺的特征峰。然而，这也可能是 4-氯苯胺的其他异构体，如 2-氯苯胺和 3-氯苯胺的特征峰。
本研究的目的是进一步通过气相色谱-质谱（GC-MS）来鉴定沉淀物。
结果显示沉淀中不存在其他苯胺衍生物。仅发现 PCA。
应进一步研究沉淀物，以解决 PCA 从牙本质中浸出的生物利用度及其细胞毒性问题。在进一步研究沉淀物之前，似乎应避免将 CHX 与 NaOCl 一起使用，以尽量减少其形成。
