A comparative in vitro evaluation of cytotoxic effects of EDTA and maleic acid: Root canal irrigants

Objective. The objective of this study was to compare aqueous solutions of ethylenediaminetetraacetic acid (EDTA) with that of maleic acid (MA) for their cytotoxic effect on Chinese hamster fibroblasts (V79) cells growing in vitro. Study design. Exponentially growing V79 cells were treated with various concentrations of EDTA (0.05% to 1.0%) or MA (0.05% to 1.0%) alone for 30 minutes. After treatment, the media was removed, cells were trypsinized, and the cytotoxic effect of EDTA or MA was analyzed by Pratt Willis test and MTT assay. Similarly surviving fraction (clonogenic assay) was performed by treating the V79 cells with different concentrations of EDTA (0.0025% to 0.25%) or MA (0.025% to 0.25%) for 30 minutes. The statistical significance between the various groups was evaluated using the one-way analysis of variance (ANOVA) and Student t test (unpaired) for 2 group comparisons. Results. There was a significant (P < .01) decrease in the cell viability in a dose-dependent manner indicating the cytotoxic effect of both EDTA and MA when compared with the control group. However, all the dilutions of EDTA were significantly (P < .01) more cytotoxic over that of MA in all 3 assays. Conclusion. This study for the first time, clearly demonstrated the significantly less toxic effect of MA at a comparable dose of EDTA, suggesting its potential for use as root canal irrigant. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: 633-638)