title: The effects of temperature on sodium hypochlorite short-term stability, pulp dissolution capacity, and antimicrobial efficacy.
abstract: The purpose of this study was to test some effects of preheating NaOCl solutions using a commercially available syringe heating device. Irrigating solution temperatures in 10-ml syringes were measured. Stability of 5.25, 2.62, and 1% NaOCl solutions for 60 min at 20, 45, and 60 degrees C was assessed using iodine/thiosulfate titration. Human pulp tissue dissolution capacity of a 1% NaOCl solution was gauged at the latter temperatures, and compared to corresponding values with a 5.25% solution at 20 degrees C. Killing efficacy of diluted NaOCl solutions against 48-h incubations of Enterococcus feacalis ATCC 29212 was compared at 45 degrees C and 20 degrees C. Using the heating device, a 20 degrees C solution reached 45 degrees C and 60 degrees C in 7 and 20 min, respectively. Solutions remained stable during the observation period. The 1% NaOCl solution at 45 degrees C dissolved pulp tissues as effectively as the 5.25% solution at 20 degrees C, while the 60 degrees C/1% solution was significantly more effective (p < 0.05). A 100-fold increase in killing efficacy was observed between corresponding NaOCl solutions at 20 degrees C and 45 degrees C.
authors.affiliation: Department of Preventive Dentistry, Periodontology, and Cariology, University of Zurich Center for Dental Medicine Zurich, Switzerland.
authors.forename: George
authors.initials: G
authors.lastname: Sirtes
authors.forename: Tuomas
authors.initials: T
authors.lastname: Waltimo
authors.forename: Marc
authors.initials: M
authors.lastname: Schaetzle
authors.forename: Matthias
authors.initials: M
authors.lastname: Zehnder
mesh_terms: D000704:Analysis of Variance; D003782:Dental Pulp / Q000187:drug effects*; D004202:Disinfectants / Q000494:pharmacology*; D004355:Drug Stability; D013293:Enterococcus faecalis / Q000187:drug effects; D006358:Hot Temperature; D006801:Humans; D012973:Sodium Hypochlorite / Q000737:chemistry / Q000494:pharmacology*; D012996:Solutions / Q000737:chemistry / Q000494:pharmacology
chemical_list: D004202:Disinfectants; D012996:Solutions; D012973:Sodium Hypochlorite