Decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine.
OBJECTIVE
To evaluate and compare ex vivo the decalcifying effect of 15% EDTA, 15% citric acid, 5% phosphoric acid and 2.5% sodium hypochlorite on root canal dentine.


METHODS
Two 2-mm-thick slices were cut from the coronal third of the root of 10 human incisors. Each slice was sectioned into two equal parts. Specimens were assigned to one of four groups (n = 10) for immersion in 20 mL of either 15% EDTA, or 15% citric acid, 5% phosphoric acid or 2.5% NaOCl, for three time periods (5, 10 and 15 min). The concentration of Ca(2+) extracted from the dentine was measured by atomic absorption spectrophometry. The amount of calcium extracted was analysed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons.


RESULTS
In the three time periods, 15% EDTA and 15% citric acid extracted the largest amount of calcium, with no significant differences between them. The 2.5% NaOCl solution extracted insignificant amounts of calcium, whereas 15% EDTA extracted 86.72% of the calcium in the first 5 min, and 15% citric acid and 5% phosphoric acid had a similar pattern of calcium removal (77.03% and 67.08% in first 5 min, respectively).


CONCLUSIONS
Solutions of 15% EDTA, 15% citric acid and 5% phosphoric acid decalcify root dentine, with most calcium extracted during the first 5 min of action. The efficacy of 15% citric acid and 15% EDTA solutions was significantly greater than that of 5% phosphoric acid solution at each time period (5, 10 and 15 min).
Pérez-Heredia
M
M
Department of Dental Pathology and Therapeutics, School of Dentistry, University of Granada, Spain.
Ferrer-Luque
C M
CM
González-Rodríguez
M P
MP
Martín-Peinado
F J
FJ
González-López
S
S
D000328:Adult; D002118:Calcium / Q000032:analysis; D019343:Citric Acid / Q000494:pharmacology; D003648:Decalcification Technique; D003786:Dental Pulp Cavity; D003804:Dentin / Q000737:chemistry* / Q000187:drug effects*; D004492:Edetic Acid / Q000494:pharmacology; D006801:Humans; D007180:Incisor; D008875:Middle Aged; D010756:Phosphoric Acids / Q000494:pharmacology; D012044:Regression Analysis; D012388:Root Canal Irrigants / Q000494:pharmacology*; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013054:Spectrophotometry, Atomic; D018709:Statistics, Nonparametric
D010756:Phosphoric Acids; D012388:Root Canal Irrigants; D019343:Citric Acid; D004492:Edetic Acid; D012973:Sodium Hypochlorite; C030242:phosphoric acid; D002118:Calcium