title: Effect of sodium hypochlorite and EDTA on mercury released from amalgam.
abstract: OBJECTIVE
  The effect of sodium hypochlorite (NaOCl) and EDTA on mercury released from dental amalgam was assessed in vitro.
  
  
  METHODS
  Fifty-six samples of dental amalgam of similar size were prepared and exposed to a 10-mL solution of either 1% NaOCl, 3% NaOCl, 10% EDTA in 1% NaOCl, or 10% EDTA in 3% NaOCl for periods of 20, 40, and 60 minutes. Mercury concentrations in the solutions were measured by using a cold-vapor atomic absorption Mercury Analyzer System, and the differences between the groups were statistically analyzed.
  
  
  RESULTS
  All amalgam samples exposed to 1% NaOCl and 3% NaOCl-either alone or in combination with EDTA-released mercury into the solutions. Mercury release was significantly higher in the test groups than in the EDTA, distilled water, or phosphate buffer controls (P <.001). Increase in the mean concentration levels of mercury in solution was time-dependent and directly related to NaOCl concentration. The addition of EDTA caused a reduction in mercury levels detected in solution, which was more significant in amalgam samples exposed to 1% NaOCl combined with EDTA (P <.001).
  
  
  CONCLUSIONS
  NaOCl solutions commonly used for root canal cleaning and shaping cause mercury release from dental amalgam and may alter its chemo-physical properties as a sealant for root perforations.
authors.affiliation: Division of Surgical, Therapeutic and Bioengineering Sciences, School of Dentistry, University of Southern California, Los Angeles 90089-0641, USA. ilan@usc.edu
authors.forename: I
authors.initials: I
authors.lastname: Rotstein
authors.forename: M
authors.initials: M
authors.lastname: Karawani
authors.forename: S
authors.initials: S
authors.lastname: Sahar-Helft
authors.forename: C
authors.initials: C
authors.lastname: Mor
authors.forename: D
authors.initials: D
authors.lastname: Steinberg
mesh_terms: D000704:Analysis of Variance; D002021:Buffers; D002614:Chelating Agents / Q000008:administration & dosage / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry*; D004202:Disinfectants / Q000008:administration & dosage / Q000737:chemistry*; D004492:Edetic Acid / Q000008:administration & dosage / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008628:Mercury / Q000032:analysis / Q000737:chemistry*; D010710:Phosphates; D012387:Root Canal Filling Materials / Q000737:chemistry; D012388:Root Canal Irrigants / Q000737:chemistry; D018915:Root Canal Preparation; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000737:chemistry*; D013054:Spectrophotometry, Atomic; D018709:Statistics, Nonparametric; D013997:Time Factors; D014867:Water
chemical_list: D002021:Buffers; D002614:Chelating Agents; D003722:Dental Alloys; D004202:Disinfectants; D010710:Phosphates; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D014867:Water; D003723:Dental Amalgam; C072894:Valiant PhD; D004492:Edetic Acid; D012973:Sodium Hypochlorite; D008628:Mercury