Effect of root canal irrigants on cervical dentine permeability to hydrogen peroxide.
OBJECTIVE
To examine the effects of various root canal irrigants on cervical dentine permeability by monitoring the diffusion of hydrogen peroxide (H(2)O(2)).


METHODS
Sixty cervical dentine discs were prepared from human third molar teeth. After removal of enamel and cementum, the outer dentine surface was etched with 17% ethylenediamine tetraacetic acid (EDTA) for 1 min. The dentine discs were randomly assigned to five groups according to the irrigant used: A, saline solution; B, 2.5% sodium hypochlorite solution (NaOCl); C, 5% NaOCl; D, 17% EDTA and 2.5% NaOCl; E, 17% EDTA and 5% NaOCl. After irrigation on the inner dentine surface with the various solutions, the diffusion of 30% H(2)O(2) was evaluated through each disc using a plastic-split chamber. H(2)O(2) was applied to the inner-side chamber, while the outer-side chamber was filled with de-ionised water. After 30 min of application of H(2)O(2), the solution in the outer-side chamber was collected to determine the concentration of H(2)O(2) using a spectrophotometer.


RESULTS
The penetration of H(2)O(2) through dentine in group E was significantly highest, followed by groups D, C, B and A respectively (one-way anova, P < 0.05).


CONCLUSIONS
Among the irrigants used, 17% EDTA and 5% NaOCl had the greatest effect in increasing dentinal permeability to H(2)O(2).
Surapipongpuntr
P
P
Restorative Department, Faculty of Dentistry, Naresuan University, Phitsanulok, Thailand. perayap@nu.ac.th
Duangcharee
W
W
Kwangsamai
S
S
Ekka
A
A
D000134:Acid Etching, Dental; D002614:Chelating Agents / Q000008:administration & dosage / Q000494:pharmacology; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D003806:Dentin Permeability / Q000187:drug effects*; D004058:Diffusion; D015194:Diffusion Chambers, Culture; D004492:Edetic Acid / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000494:pharmacology*; D016369:Smear Layer; D012965:Sodium Chloride; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology; D013053:Spectrophotometry; D013997:Time Factors; D019237:Tooth Cervix / Q000187:drug effects*; D055815:Young Adult
D002614:Chelating Agents; D012388:Root Canal Irrigants; D012965:Sodium Chloride; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite