title: [Influence of zirconia content on translucency of zirconia-toughened alumina glass-infiltrated ceramic].
abstract: OBJECTIVE
  The objective of this study is to investigate the influence of zirconia content which is 0-30.0% weight percentage of matrix on translucency of zirconia-toughened alumina glass-infiltrated ceramics.
  
  
  METHODS
  Seven groups were divided according to different weight percentage of zirconia (0, 2.5%, 5.0%, 7.5%, 10.0%, 20.0% and 30.0%). After sintering, infiltrating and polishing, spectral transmittance was determined with spectrophotometer under D65 standard source. Contrast ratio was also tested by whiteness colorimeter.
  
  
  RESULTS
  With mass fraction of zirconia increasing from 0 to 30.0%, spectral transmittance reduced from 0.406% to 0.058%, while contrast ratio value increased from 0.849 +/- 0.005 to 1.015 +/- 0.006. When zirconia content was 10.0%, contrast ratio was 0.990 +/- 0.008. When it was more than 10.0%, transmission rate of the downward trend and contrast ratio of the rising trend became flat.
  
  
  CONCLUSIONS
  Zirconia content has a direct impact on translucency of zirconia-toughened alumina glass-infiltrated ceramic, which is essentially opaque when zirconia content is 10.0%. When mass fraction of zirconia is more than 10.0%, the influence of zirconia content is reduced.
authors: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu 610041, China.
authors: Zhi-Ling
authors: ZL
authors: Yan
authors: Su-Qin
authors: SQ
authors: Xian
authors: Tao
authors: T
authors: Tan
authors: Yun-Mao
authors: YM
authors: Liao
authors: Xiao-Yu
authors: XY
authors: Yang