title: [A study on the color difference between Au-Pt alloy porcelain and Ni-Cr alloy porcelain].
abstract: OBJECTIVE
  To investigate the color difference between Au-Pt alloy porcelain and Ni-Cr alloy porcelain.
  
  
  METHODS
  30 metal-ceramic specimens with different dentin porcelain thickness were fabricated with two types of metal-ceramic alloy, each type of alloy had 15 specimens. L*, a*, b* were measured after opaque porcelain was applied, and dentin porcelain was fired 1, 3, 5, 7 times by MINOLTA CR-100. Then delta E was calculated which reflected the color difference between high-gold alloy porcelain and Ni-Cr alloy porcelain.
  
  
  RESULTS
  Comparing with Ni-Cr alloy porcelain, the color of Au-Pt alloy porcelain was reddish, yellowish and less bright. The delta E between high-gold alloy porcelain and Ni-Cr alloy porcelain in shade A2 was largest when opaque porcelain was applied. It decreased when dentin porcelain was applied. It became smallest when fired 3 times, and increased along with the increase of fire times. It was larger than 1.5 except firing 3 times. When dentin porcelain was applied, delta E which was larger than 1.5 among different dentin porcelain thickness decreased along with the increase of dentin porcelain thickness.
  
  
  CONCLUSIONS
  The color difference between the two types of metal-ceramic alloy should be carefully taken into account in order to improve the quality of color matching.
authors.affiliation: Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Li
mesh_terms: D002857:Chromium; D002858:Chromium Alloys; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D006047:Gold Alloys; D006801:Humans; D016876:Metal Ceramic Alloys; D009532:Nickel; D010984:Platinum; D017797:Prosthesis Coloring
chemical_list: D002858:Chromium Alloys; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D002857:Chromium; D003776:Dental Porcelain; D010984:Platinum; D009532:Nickel