The Antibacterial Efficacy and In Vivo Toxicity of Sodium Hypochlorite and Electrolyzed Oxidizing (EO) Water-Based Endodontic Irrigating Solutions

Abstract

The objective of this study was to evaluate the antibacterial efficacy against Enterococcus faecalis and Streptococcus mutans and in vivo toxicity using embryonic zebrafish assays of sodium hypochlorite (NaOCl) and electrolyzed oxidizing (EO) water (containing hypochlorous acid (HOCl))-based root canal irrigating solutions. Methodology: Using 100 µL microbial count of 1 × 10 8 cfu/mL Enterococcus faecalis to mix with each 10 mL specimen of NaOCl or HOCl for designed time periods. The above protocol was also repeated for Streptococcus mutans. The concentration of viable microorganisms was estimated based on each standardized inoculum using a plate-count method. Zebrafish embryo assays were used to evaluate acute toxicity. Results: All the HOCl or NaOCl treatment groups showed > 99.9% antibacterial efficacy against Enterococcus faecalis and Streptococcus mutans. Zebrafish embryos showed almost complete dissolution in 1.5% NaOCl within 5 min. Both survival rates after being treated with 0.0125% and 0.0250% HOCl for 0.5 min or 1.0 min were similar to that of E3 medium. Conclusions: Both NaOCl and HOCl revealed similar antibacterial efficacy (> 99.9%) against Enterococcus faecalis and Streptococcus mutans. While 1.5% NaOCl fully dissolved the Zebrafish embryos, both 0.0125% and 0.0250% HOCl showed little in vivo toxicity, affirming its potential as an alternative irrigation solution for vital pulp therapy.

Pattern of disinfectants use and their adverse effects on the consumers after COVID-19 outbreak

“…Some people, mostly low-income people, use Sodium hypochlorite bleach to disinfect their hands due to its low cost and availability. Although low-concentration of sodium hypochlorite bleach (0.05%) can be used for hand disinfection [ 29 – 31 ], uses of sodium hypochlorite bleach with high concentration are limited unless in emergency conditions. Repeated use of sodium hypochlorite bleach with inappropriate concentrations can cause damage to the skin of the hands and respiratory problems for these people.…”

In vitro inhibitory effects of commercial antiseptics and disinfectants on foodborne and environmental bacterial strains

“…This could explain the low activity of bleach if it is in the process of decomposition or originally exposed to heat and light for long periods. Decreasing the concentration by dilution would reduce activity as the active ingredient concentration would be reduced 13,14 .…”

“…This would explain its inhibitory effects on E. coli and Bacillus sp. Chloroxylenol is the active ingredient in Camel antiseptic; it is very effective against a wide range of gram-positive and some gram-negative bacteria 2,14 . It disrupts cell wall due to its phenolic nature, inhibits the functions of enzymes associated with antimicrobial resistance and induces morphological changes especially in E. coli 2 .…”

Experimental Solution of Chitosan and Nanochitosan on Wettability in Root Dentine: In Vitro Model Prior Regenerative Endodontics

“…For chelating agents, the wettability of the substrate is related to the surface roughness, which is significantly modified during demineralization [ 26 ]. Therefore, high chelation corresponds to a greater irregularity of the tissue surface and, consequently, lower wettability [ 6 ].…”

“…This value was even more remarkable for the experimental groups that supported chelation. The HOCl has an extraordinary bactericidal effect due to its high reduction/oxidation potential (ORP) greater than 1100 mV and has been recommended as an alternative irrigation solution for vital pulp therapy [ 26 ]. The inclusion of hypochlorous acid, alone or in combination with EDTA (G4), showed the chelating effect, the integrity of the organic tissue, and the damage that promotes a cumulative chelating effect on the surface topography of the dentin when associated with EDTA.…”