The properties of chlorhexidine and undesired effects of its use in endodontics

The purpose of this article was to review the literature on the properties of chlorhexidine (CHX) and the adverse effects that may occur from its use in endodontics. In addition, adverse effects that may result from its use, such as dark staining of teeth, chemical interaction with sodium hypochlorite and formed flocculate, biologic hazards, and interactions with the filling material were evaluated.

Relevant publications on the use CHX in endodontics were thoroughly reviewed from the literature published between the years 2007 and 2014.

The authors conducted an electronic search using the English language databases Medline and PubMed.

According to the reviewed studies, it was concluded that CHX has proven antimicrobial activity, excellent substantivity, low surface tension, and low cytotoxicity and genotoxicity that depend on the dose and exposed area. There is scientific evidence showing the possibility of tooth staining and formation of brown precipitate when its use is associated with sodium hypochlorite. On the other hand, it is not well established that its use interferes with the quality of endodontic fillings. With respect to the biologic risks, the degradation of CHX may generate para-chloroaniline and free radicals, which are harmful to the vital tissues. There is no established consensus on the potential risk of CHX.

The final considerations of this review will encourage researchers to seek scientific evidence demonstrating the safety of the use and applicability of CHX in endodontic therapy.