Table 2.

Studies focused on CHX concentration to analyze PCA formation

Study ID	Study design	Identification of the precipitate	Removal/ prevention of the precipitate	Analysis method	Outcome
Barbin et al.[22]	In vitro	No	No	Mass spectrometry, HPLC	ROS liberation was seen with the combination of CHX and Ca(OH)2
Barbin et al.[23]	In vitro	No	No	GC-MS	PCA and ROS were the by-products of the 2% CHX aqueous solution
Câmara De Bem et al.[24]	In vitro	No	No	GC-MS	2% CHX gel and solution may degrade into PCA, oCA, mCA, ROS, and organochlorines (ortho-chlorophenyl isocyanate and 2-amino-5-chlorobenzonitrile) regardless of storage conditions or time

GC-MS = gas chromatography–mass spectrometry, HPLC = high-performance liquid chromatography, mCA = meta-chloroaniline, oCA = ortho-chloroaniline, ROS = reactive oxygen species