Assessment of genotoxic effect of maleic acid and EDTA: A comparative in vitro experimental study

Objectives: This study aims to evaluate and compare the genotoxic and apoptotic effect of aqueous solutions of ethylenediaminetetraacetic acid (EDTA) with that of maleic acid (MA) using Chinese hamster lung fibroblast (V79) cells growing in vitro. Materials and methods: Exponentially growing V79 cells were treated with various concentrations of EDTA or MA alone for 30 min, and genotoxic effect was analyzed by micronucleus as well as comet assays and the type of cell death by apoptotic cell measurements using microscopic and flow cytometric methods. For all the experiments, H₂O₂ was used as a positive control. Results: Treatment of V79 cells with H₂O₂ resulted in significantly (P < 0.001) increased micronuclei and levels of DNA damage, whereas, EDTA/MA alone treated cells did not show significant increase of MN frequencies and comet parameters even at their higher concentrations when compared with that of untreated control. V79 cells treated with EDTA/MA for 30 min showed a nonsignificant increase in the percentage of apoptotic and necrotic cells at their lower concentrations (0.025 and 0.05 % for EDTA and MA, respectively). However, at higher concentrations, i.e., >IC₅₀ (0.1 and 0.5 %) for EDTA and MA resulted in increased number of apoptotic and necrotic cells when compared with the untreated group. Conclusions: This study clearly demonstrates that MA and EDTA are not potentially genotoxic agents and MA induced lesser apoptotic/necrotic death than that of EDTA at their clinically relevant doses. Clinical relevance: MA may have a better clinical acceptability with comparable smear layer removal ability. Hence, the results presented here might be an additional supporting evidence for the use of MA in endodontic practice.