title: Comparative evaluation of calcium hypochlorite and sodium hypochlorite on soft-tissue dissolution.
abstract: BACKGROUND
  The aim of this study was to compare in vitro the tissue-dissolution properties of 5% and 10% calcium hypochlorite (Ca(OCl)(2)) with two concentrations (1.36% and 4.65%) of proprietary sodium hypochlorite (NaOCl) on bovine muscle tissue.
  
  
  METHODS
  The available chlorine concentration of each solution was determined using iodometric titration. Tissue specimens from bovine muscle were weight adjusted (50 ± 5 mg). Ten tissue specimens in each group were immersed in 5 mL each test solution, removed after 5 minutes, blotted dry, and weighed. The process was repeated every 5 minutes with a fresh 5-mL aliquot of the test solution for 60 minutes or until complete tissue dissolution, whichever was quickest. The percentage weight loss of the specimens was calculated over the experimental period.
  
  
  RESULTS
  Available chlorine concentrations of the irrigants ranged from 1.36% to 4.65%. All solutions dissolved tissue completely after 60 minutes except 5% Ca(OCl)(2) (99.4% dissolution). Between the 35- and 60-minute test readings, there were no significant differences between the solutions. Chlorax (4.65% NaOCl) (Cerkamed Group, Nisko, Poland) dissolved tissue quicker during the first 35 minutes (P < .05). In this period, the weight loss with 10% Ca(OCl)(2) differed from Chlorax at all time intervals except at 5 and 35 minutes (P < .05); 5% Ca(OCl)(2) showed no significant differences with 10% Ca(OCl)(2) and Tesco bleach (1.36% NaOCl) (Tesco Stores Ltd, Chestnut, UK) in the first 35 minutes except at the 5-minute measurement.
  
  
  CONCLUSIONS
  Within the limitations of this study, Chlorax (4.65% NaOCl) dissolved tissue faster than the Ca(OCl)(2) solutions and Tesco thin bleach (1.36% NaOCl) over the first 35 minutes, but there were no significant differences among the solutions thereafter.
authors.affiliation: Department of Restorative Dentistry, Dundee Dental Hospital and School, Dundee, United Kingdom.
authors.forename: Arindam
authors.initials: A
authors.lastname: Dutta
authors.forename: William P
authors.initials: WP
authors.lastname: Saunders
mesh_terms: D000818:Animals; D057886:Bleaching Agents / Q000008:administration & dosage / Q000494:pharmacology; D017610:Calcium Compounds / Q000008:administration & dosage*; D002417:Cattle; D002713:Chlorine / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D009132:Muscles / Q000187:drug effects*; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D012973:Sodium Hypochlorite / Q000008:administration & dosage*; D012997:Solvents / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors
chemical_list: D057886:Bleaching Agents; D017610:Calcium Compounds; D012388:Root Canal Irrigants; D012997:Solvents; C004488:calcium hypochlorite; D002713:Chlorine; D012973:Sodium Hypochlorite