Insight into the Reaction of Alexidine with Sodium Hypochlorite: A Potential Error in Endodontic Treatment

Abstract

Therapeutic success in endodontic treatment depends on successful infection control. Alexidine dihydrochloride (ALX) was recently proposed as a potential alternative to 2% chlorhexidine (CHX) as it possesses similar antimicrobial properties, expresses substantivity and does not produce p-chloroaniline (PCA) when mixed with sodium hypochlorite (NaOCl). However, the products released in this reaction have not been described to date. The aim of this study was to identify detected chemical compounds formed in the reaction of ALX and NaOCl with the ultra-high-performance liquid chromatography–mass spectrophotometry (UHPLC-MS) method and assess whether precipitates and PCA are formed in this reaction. Solutions of ALX were mixed with the equivalent volume of 2% and 5.25% (w/v) NaOCl solutions. As control, 2% (w/v) CHX was mixed with 2% and 5.25% (w/v) NaOCl. Samples were subjected to the UHPLC-MS analysis. The mixture of ALX and NaOCl resulted in a yellowish precipitate formation, the amount of which depended on NaOCl concentration. Interaction of ALX and NaOCl resulted in the production of aliphatic amines. No PCA was formed when NaOCl was mixed with ALX. However, for the first time, we identified the possible products of the interaction. The interaction between NaOCl and ALX results in the formation of aliphatic amines; therefore, these compounds should not be mixed during endodontic treatment.

Effect of Alexidine Dihydrochloride on the Bond Strength of Resin-Based Sealer to Dentin

“…11,19 It was recommended that ALX and NaOCl should be used without mixing during endodontic irrigation since aliphatic amines which are the products of this reaction have neurotoxic properties. 13 Also in our study ALX and NaOCl did not used consecutively.…”

“…19,20 On the contrary, in a recent study, it was reported that a yellowish precipitate was formed by the interaction of NaOCl and ALX, but PCA was not formed. 13 Unlike PCA 12 , SEM (Scanning Electron Microscope) images in previous studies revealed that this precipitate did not occlude dentin tubules, so does not compromise the quality of the root canal filling in terms of microleakage. 11,19 It was recommended that ALX and NaOCl should be used without mixing during endodontic irrigation since aliphatic amines which are the products of this reaction have neurotoxic properties.…”

“…Alexidine dihydrochloride (ALX), which is chemically similar to CHX 7 and has positive effects on cancer 8 , aging, and age related disorders 9 , is considered as a potential endodontic irrigation solution. [10][11][12][13][14] CHX and ALX bind to lipopolysaccharide and lipoteichoic acid; however, ALX shows more affinity for them than CHX. 15,16 While the bactericidal activity and minimum inhibitory concentration values of CHX and ALX are similar, ALX reaches these values much more quickly, and it shows a more rapid antibacterial effect, more bacterial permeability than CHX and more antimicrobial substantivity.…”

“…21 If ALX is combined with NaOCl, it can be a potential endodontic final irrigation solution. [10][11][12][13][14] Moreover, it may be an alternative to CHX due to its activity on E. faecalis and Candida albicans. 24 Adhesion of the root canal filling is one of the important clinical factor in endodontic treatment.…”

Antiseptic drugs and disinfectants with experience of the second year of COVID-19 pandemic-related side effects

“…Drug–drug interactions : To enhance the bactericidal effect of sodium hypochlorite, other agents have been advocated in root canal irrigation protocols. Although it was already known that a mixture of sodium hypochlorite with chlorhexidine produces p-chloroaniline as a toxic by-product, as well as brown precipitates, the mixture with alexidine dihydrochloride results in formation of aliphatic amines and should also be avoided ( Czopik et al, 2021 ) [E].…”