title: Effect of super-oxidized water, sodium hypochlorite and EDTA on dentin microhardness.
abstract: The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 µm from the root canal lumen (distance 1), and the other at approximately 500-1000 µm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.
authors.affiliation: Department of Endodontics, School of Dentistry, PUCRS - Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Alexandre Corrêa
authors.initials: AC
authors.lastname: Ghisi
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, UFRGS -Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Patrícia Maria Poli
authors.initials: PM
authors.lastname: Kopper
authors.affiliation: Department of Conservative Dentistry, School of Dentistry, UFRGS -Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Flávia E R
authors.initials: FE
authors.lastname: Baldasso
authors.affiliation: Department of Endodontics, School of Dentistry, PUCRS - Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Caroline P
authors.initials: CP
authors.lastname: Stürmer
authors.affiliation: Department of Endodontics, Dentistry, Warwick Medical School, Warwick, United Kingdom.
authors.forename: Giampiero
authors.initials: G
authors.lastname: Rossi-Fedele
authors.affiliation: Department of Endodontics, Dentistry, Warwick Medical School, Warwick, United Kingdom.
authors.forename: Liviu
authors.initials: L
authors.lastname: Steier
authors.affiliation: Department of Endodontics, School of Dentistry, PUCRS - Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: José Antonio Poli de
authors.initials: JA
authors.lastname: Figueiredo
authors.affiliation: Department of Endodontics, School of Dentistry, PUCRS - Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Renata Dornelles
authors.initials: RD
authors.lastname: Morgental
authors.affiliation: Department of Endodontics, School of Dentistry, PUCRS - Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Fabiana Vieira
authors.initials: FV
authors.lastname: Vier-Pelisser
mesh_terms: D000818:Animals; D002417:Cattle; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000648:ultrastructure; D003804:Dentin / Q000187:drug effects* / Q000648:ultrastructure; D004492:Edetic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D006244:Hardness; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000494:pharmacology*; D008422:Materials Testing; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014092:Tooth Root / Q000187:drug effects / Q000648:ultrastructure
chemical_list: D012388:Root Canal Irrigants; C118085:superoxidized water; D004492:Edetic Acid; D006861:Hydrogen Peroxide; D012973:Sodium Hypochlorite