title: [Analysis on content of Ni-Cr in gingival and blood of hares after wearing non-noble porcelain-fused-to-metal crown].
abstract: OBJECTIVE
  Purpose of the study was to investigate the content of Nickel (Ni) and Chromium (Cr) ion in gingival tissue and blood, and to discuss the reason of gray line in gingival after wearing non-noble Porcelain-Fused-to-Metal crown.
  
  
  METHODS
  38 rabbits were selected as experimental animals which were divided into three groups: control group, group 1 (3 months) and group 2 (6 months). The content of Ni and Cr ion in gingival tissue and blood was detected by atomic absorption spectrometer.
  
  
  RESULTS
  The amount of Ni and Cr in group 2 was significantly higher than that in other groups (P < 0.05) . There was no difference between group 1 and control group (P > 0.05) .
  
  
  CONCLUSIONS
  The reason of gingival colouration might be the electrochemical corrosion. The metal ion was released in gingival tissue and blood.
authors.affiliation: Dept. of Prosthodontics, Zunyi Medical College, Zunyi 563003, China.
authors.forename: Guo-wei
authors.initials: GW
authors.lastname: Zhu
authors.forename: Xiao-hong
authors.initials: XH
authors.lastname: Yang
authors.forename: Li-ya
authors.initials: LY
authors.lastname: Chen
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
mesh_terms: D000818:Animals; D002857:Chromium / Q000097:blood / Q000737:chemistry*; D003442:Crowns; D003776:Dental Porcelain; D005881:Gingiva / Q000737:chemistry*; D034621:Hares; D009532:Nickel / Q000097:blood / Q000737:chemistry*
chemical_list: D002857:Chromium; D003776:Dental Porcelain; D009532:Nickel