Cytotoxicity of chlorhexidine-hydrogen peroxide combination in different concentrations on cultured human periodontal ligament fibroblasts

Abstract

Background:

A strong antimicrobial synergism between chlorhexidine (CHX) and hydrogen peroxide (H ₂O ₂) has been reported, but there is not enough data on the cytotoxicity of this combination. The primary aim of this study was to evaluate the cytotoxicity of CHX-H ₂O ₂ combination in different concentrations and secondary aim is to assess the influence of H ₂O ₂ on cytotoxicity of CHX on cultured human periodontal ligament (PDL) fibroblasts.

Materials and Methods:

The PDL cells were cultured from healthy human third molar teeth and were exposed to six prepared solutions (0.2% and 2% CHX separately and in combination with 1% and 3% H ₂O ₂). The MTT assay was applied to assess their effects on the viability of the PDL cells. Two-way analysis of variance approach and subgroup analysis was performed to evaluate the differences in mean cell viability values. A level of P < 0.05 was considered as statistically significant.

Results:

All tested solutions were toxic to PDL cells. There was a significant interaction effect between CHX and H ₂O ₂. The 2% CHX combined with 3% H ₂O ₂ was the most and 0.2% CHX was the least cytotoxic solutions. The 2% CHX was significantly more toxic than 0.2% CHX and H ₂O ₂ combinations. The cytotoxicity of 0.2% CHX and H ₂O ₂ combinations did not significantly rise by increasing the concentration of H ₂O ₂ from 1% to 3%.

Conclusion:

H ₂O ₂ affected the cytotoxicity of CHX in a variable concentration-dependent manner. Based on the results of this study, it can be concluded that 2% CHX alone and in combination with either 1 or 3% H ₂O ₂ are significantly more toxic than 0.2% CHX alone and in combination with 1 and 3% H ₂O ₂. Therefore, to benefit from the synergistic antimicrobial effect between CHX and H ₂O ₂, with a minimal cytotoxicity, it is recommended to use 0.2% concentration of CHX combined with 3% H ₂O ₂.