title: Intracanal Irrigating Solutions Prior to Calcium Hydroxide Medication and Its Effects on Root Dentin Strength.
abstract: The aim of this study was to assess the effects of intracanal irrigation with sodium hypochlorite (NaOCl) and ethylenediaminetetracetic acid (EDTA) prior to calcium hydroxide medication on the compressive strength of root dentin. Forty-eight roots with single and straight canals were instrumented with a crown-down technique using Flexofile files and Gates Glidden burs, under 0.9% sodium chloride (NaCl) irrigation. Root canals were randomly separated into 4 groups (n=12), according to the irrigating solution: Control Group, 0.9% NaCl; GroupNaOCl, 1% NaOCl; GroupEDTA, 17% EDTA; and GroupEDTA+NaOCl, 17% EDTA and 1% NaOCl. Solutions remained for 40 min, renewed every 10 min, except for GroupEDTA+NaOCl, where the solutions were alternated every 10 min. Canals were dried and filled with calcium hydroxide paste, and radiographed. Each canal was sealed and stored at 37 °C for 30 days. After this period, the roots were cut 1 mm below the cementoenamel junction and 6 mm apically from this point in order to obtain 6 mm-long cylinders. The compressive test was conducted with a crosshead speed of 1 mm/min. The means (±SD) (MPa) of compressive strength were: Control Group, 151.23±94.36; GroupNaOCl, 167.50±57.25; GroupEDTA, 108.79±99.88; GroupEDTA+NaOCl, 60.12±92.10. Significant statistical differences among groups were found (ANOVA and Tukey, a=5%, p=0.02). Control Group and GroupNaOCl showed higher means of compressive strength than GroupEDTA+NaOCl. Intracanal irrigation with 17% EDTA and 1% NaOCl produced a significant reduction of dentin compressive strength 30 days after medication with calcium hydroxide.
authors.affiliation: Departament of Dentistry, UFSC - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Leila Clarisse
authors.initials: LC
authors.lastname: Hillesheim
authors.affiliation: Departament of Dentistry, UFSC - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Juliara Bellina
authors.initials: JB
authors.lastname: Hoffmann
authors.affiliation: Departament of Dentistry, UFSC - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Daniela Peressoni Vieira
authors.initials: DP
authors.lastname: Schuldt
authors.affiliation: Departament of Dentistry, UFSC - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Maybell
authors.initials: M
authors.lastname: Tedesco
authors.affiliation: Departament of Dentistry, UFSC - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Eduardo Antunes
authors.initials: EA
authors.lastname: Bortoluzzi
authors.affiliation: Departament of Dentistry, UFSC - Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
authors.forename: Cleonice Silveira
authors.initials: CS
authors.lastname: Teixeira
mesh_terms: D002126:Calcium Hydroxide / Q000008:administration & dosage*; D003804:Dentin / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D014092:Tooth Root / Q000187:drug effects*
chemical_list: D012388:Root Canal Irrigants; D002126:Calcium Hydroxide