title: [A prospective follow-up study on the impact of urinary excretions of nickel and chromium after dental restoration by nickel-chromium based alloys].
abstract: OBJECTIVE
  To explore whether the dental restoration of nickel-chromium (Ni-Cr) based alloys will lead to extra excretions of urinary Ni and Cr.
  
  
  METHODS
  Urinary Ni and Cr were repeatedly measured in 33 patients before and 2 months after the dental restoration of Ni-Cr alloys. The associations between alloy restoration and urinary Ni or Cr were analyzed by paired t test and general linear model of repeated measures.
  
  
  RESULTS
  A slightly higher urinary Ni was found in patients after 2 month of the alloy restoration, but the difference was not statistically significant (before: 46.4 microg x mol(-1) crea; after: 67.6 microg x mol(-1) crea; P=0.063). This difference was only in female subjects (before: 44.8 microg x mol(-1) crea; after: 73.7 microg x mol(-1) crea; P=0.068). A significant higher urinary Cr was found in patients after 2 month of the alloy restoration (before: 57.0 microg x mol(-1) crea; after: 99.4 microg x mol(-1) crea; P=0.024). This significant difference was only in female subjects (before: 59.8 microg x mol(-1) crea; after: 124.4 microg x mol(-1) crea; P=0.023). General linear models of repeated measurements showed that urinary excretions of Ni and Cr were associated with the number of restoration and the area of metal basis uncovered with porcelain.
  
  
  CONCLUSIONS
  Dental restoration of Ni-Cr alloy might lead to the enhanced excretions of urinary Ni and Cr.
authors.affiliation: Dept. of Prosthodontics, Shanghai Stomatological Diseases Center, Shanghai 200001, China.
authors.forename: Xinming
authors.initials: X
authors.lastname: Cao
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Xia
authors.forename: Biyao
authors.initials: B
authors.lastname: Xu
authors.forename: Qingping
authors.initials: Q
authors.lastname: Shen
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhong
authors.forename: Qingwu
authors.initials: Q
authors.lastname: Jiang
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
mesh_terms: D002857:Chromium; D002858:Chromium Alloys; D003776:Dental Porcelain; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009532:Nickel; D011446:Prospective Studies
chemical_list: D002858:Chromium Alloys; D002857:Chromium; D003776:Dental Porcelain; C066018:nichrome; D009532:Nickel