Toxicity of irrigating solutions and pharmacological associations used in pulpectomy of primary teeth.

ABSTRACT

AIM: To evaluate the in vitro toxicity of irrigating solutions and pharmacological associations used in the pulpectomy of primary teeth. METHODOLOGY: The cell viability (MTT), lipid peroxidation (TBARS), alkaline comet assay and GEMO tests were performed to evaluate the cytotoxicity and genotoxicity of solutions sodium hypochlorite (1% and 2.5%), 2% chlorhexidine, 6% citric acid and 17% EDTA, which were tested, individually and in association, exposing human peripheral blood mononuclear cells (MTT, TBARS and alkaline comet assay), at 24 and 72 h, and dsDNA (GEMO). After performing the Kolmogorov-Smirnov test, data were analysed by anova followed by Dunnett's post hoc test, and Kruskal-Wallis followed by Dunn post hoc test. A significance level was established at P < 0.05. RESULTS: All irrigating solutions and pharmacological associations reduced cell viability at 24 h (P < 0.05). These reductions were maintained after 72 h, except for EDTA and associations of sodium hypochlorite (1% and 2.5%) with EDTA and of chlorhexidine with EDTA. Lipid peroxidation at 24 h was caused by EDTA and by 2.5% sodium hypochlorite with EDTA; it was also caused at 72 h by sodium hypochlorite (1% and 2.5%) and the three associations with citric acid (P < 0.05). All groups caused DNA damage when assessed by the alkaline comet assay, at 24 h and 72 h (P < 0.05). In the GEMO assay, all groups caused dsDNA damage (P < 0.05), except for chlorhexidine with EDTA. CONCLUSION: All groups showed some level of toxicity. Amongst the main solutions, chlorhexidine presented less cytotoxic potential. EDTA was the least cytotoxic of the auxiliary irrigant solutions, and the association of these two solutions showed the lowest toxicity potential amongst all groups.