title: [Effect of five kinds of pigments on the chromaticity of dental zirconia ceramic].
abstract: OBJECTIVE
  All-ceramic dental restorations should match the colour of the natural teeth in order to fulfill aesthetic demands. The goal of this study was to evaluate the colouration of zirconia ceramic by adding five kinds of pigments. The influence of the pigments concentrations on the chromaticity were also analysed.
  
  
  METHODS
  Different concentrations of five kinds of pigments were added on zirconia powder, then compacted at 200MPa using cold isostatic pressure, sintered to 1400 degrees centigrade and hold for two hours. The chromaticity of sintered bodies were measured with chroma meter.
  
  
  RESULTS
  The colours achieved by the different pigments were presented in the CIELab system. The a* value increased with the added amount of Er(2)O(3), while b* value raised with the increasing amount of CeO(2) and Pr(6)O(11). However, three pigments failed to decrease L* value and the sintered body looked too bright. The sintered bodies were brown when adding Fe(2)O(3) to zirconia. Adding MnO2 could decrease the L* value of sintered bodies significantly, but had little influence on the a* and b* value.
  
  
  CONCLUSIONS
  Five kinds of colorized zirconia ceramic could cover with the chromaticity range of dental ceramic which necessitate further investigation.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200011, China. huanghui_68@126.com
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.forename: Yuan-li
authors.initials: YL
authors.lastname: Zheng
authors.forename: Fu-qiang
authors.initials: FQ
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.forename: Lian
authors.initials: L
authors.lastname: Gao
mesh_terms: D003116:Color; D004396:Coloring Agents / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide