Cytotoxic effects of two acid solutions and 2.5% sodium hypochlorite used in endodontic therapy.
OBJECTIVE
To evaluate the cytotoxicity of 15% citric acid, 5% phosphoric acid and 2.5% NaOCl on cultured fibroblasts using MTT colorimetric assay.


METHODS
Irrigating solutions of 5% phosphoric acid, 15% citric acid, and 2.5% NaOCl, diluted at 0.1% and 0.5%, were applied to cell cultures of 3T3L1 fibroblasts. The cell viability was determined by means of MTT colorimetric assay after a period of 1, 6 and 24 hours. Percentages of cell viability were analyzed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons.


RESULTS
The percentage of cell viability diminished progressively over a 24 hour period in all solutions at both dilutions. At 0.1% dilution, 2.5% NaOCl (63.39%) and 15% citric acid (53.91%) showed the highest percentage of cell viability (p=0.083). At 0.5% dilution, 2.5% NaOCl again showed the highest cell viability value (48.51%).


CONCLUSIONS
The irrigating solution with the highest percentage of cell viability was 2.5% NaOCl at both 0.1% and 0.5% dilutions. A very low percentage of cell viability was obtained with 15% citric acid and 5% phosphoric acid at 0.5% dilution.
Navarro-Escobar
Esther
E
Department of Dental Pathology and Therapeutics, School of Dentistry, University of Granada, Granada, Spain.
González-Rodríguez
María-Paloma
MP
Ferrer-Luque
Carmen-María
CM
D002478:Cells, Cultured; D019343:Citric Acid / Q000494:pharmacology*; D003603:Cytotoxins / Q000008:administration & dosage / Q000494:pharmacology*; D003764:Dental Materials / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects*; D010756:Phosphoric Acids / Q000494:pharmacology*; D012390:Root Canal Therapy; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology*
D003603:Cytotoxins; D003764:Dental Materials; D010756:Phosphoric Acids; D019343:Citric Acid; D012973:Sodium Hypochlorite; C030242:phosphoric acid