title: Effect of sodium hypochlorite on dentin microhardness.
abstract: This study was designed to evaluate the effect on root dentin microhardness of 2.5% and 6% sodium hypochlorite solutions for various irrigation periods. Forty-two bovine roots were divided into seven groups. The control group was irrigated with saline. The experimental samples were continuously irrigated with 2.5% or 6% NaOCl for 5, 10, or 20 min. Microhardness was measured at depths of 500 mum, 1000 mum, and 1500 mum from the lumen. A decrease in microhardness was found at 500 mum between the control and samples irrigated with 6% NaOCl and 2.5% NaOCl (p = 0.352, p = 0.084 respectively) at all irrigation periods. There also was a significant difference in groups irrigated for 10 or 20 min (p = 0.001, p < 0.001 respectively). At all distances, the decrease in microhardness was more marked after irrigation with 6% NaOCl than 2.5% NaOCl.
authors.affiliation: Department of Endodontics, the Hebrew University-Hadassah School of Dental Medicine. slutsky@netvision.net.il
authors.forename: Iris
authors.initials: I
authors.lastname: Slutzky-Goldberg
authors.forename: Manal
authors.initials: M
authors.lastname: Maree
authors.forename: Reuven
authors.initials: R
authors.lastname: Liberman
authors.forename: Ilana
authors.initials: I
authors.lastname: Heling
mesh_terms: D000818:Animals; D002417:Cattle; D003804:Dentin / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006244:Hardness / Q000187:drug effects*; D008422:Materials Testing; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000633:toxicity*; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000633:toxicity*
chemical_list: D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite