title: Factors affecting mercury release from dental amalgam exposed to carbamide peroxide bleaching agent.
abstract: OBJECTIVE
  To assess, in vitro, the effects of aging and surface polishing on mercury release from dental amalgams exposed to 10% carbamide peroxide at two pH levels.
  
  
  METHODS
  Samples of fresh and aged amalgam, polished and unpolished, were treated with 10% carbamide peroxide at pH 4.5 and at pH 6.5 for periods of 1, 4, 7, 10 and 13 days. At each time period, mercury concentrations in solution were measured using a cold-vapor atomic absorption mercury analyzer system and compared to control samples treated with phosphate buffer.
  
  
  RESULTS
  Amalgam samples exposed to 10% carbamide peroxide released significantly more mercury in solution than samples exposed to phosphate buffer controls. Mercury release was time-dependent and significantly higher in aged amalgam than in fresh amalgam (P < 0.001). Mercury release was also pH-dependent and higher in unpolished amalgam.
authors.affiliation: Division of Surgical Therapeutic and Bioengineering Sciences, University of Southern California School of Dentistry, 925 West 34th Street, DEN 310, Los Angeles, CA 90089-0641, USA. ilan@usc.edu
authors.forename: Ilan
authors.initials: I
authors.lastname: Rotstein
authors.forename: Yael
authors.initials: Y
authors.lastname: Avron
authors.forename: Hagai
authors.initials: H
authors.lastname: Shemesh
authors.forename: Hatice
authors.initials: H
authors.lastname: Dogan
authors.forename: Chaim
authors.initials: C
authors.lastname: Mor
authors.forename: Doron
authors.initials: D
authors.lastname: Steinberg
mesh_terms: D000704:Analysis of Variance; D000077463:Carbamide Peroxide; D003723:Dental Amalgam / Q000737:chemistry*; D003775:Dental Polishing; D019554:Dental Restoration Wear; D004338:Drug Combinations; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008628:Mercury / Q000032:analysis*; D016877:Oxidants; D010545:Peroxides; D018709:Statistics, Nonparametric; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives*
chemical_list: D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D000077463:Carbamide Peroxide; D003723:Dental Amalgam; D014508:Urea; D008628:Mercury