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[A study on the color difference between Au-Pt alloy porcelain and Ni-Cr alloy porcelain]
Yong Li1, Yunfeng Zhao, Hong Li
1Department of Prosthodontics, West China College of Stomatology, Sichuan University, Chengdu 610041, China.
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.
Conclusion:
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.
