title: [Effect of compaction pressure on the properties of dental machinable zirconia ceramic].
abstract: OBJECTIVE
  To investigate the effect of compaction pressure on the linear shrinkage, sintering property and machinability of the dental zirconia ceramic.
  
  
  METHODS
  The nano-size zirconia powder was compacted at different isostatic pressure and sintered at different temperature. The linear shrinkage of sintered body was measured and the relative density was tested using the Archimedes method. The cylindrical surface of pre-sintering blanks was traversed using a hard metal tool. Surface and edge quality were checked visually using light stereo microscopy.
  
  
  RESULTS
  The sintering behaviour depended on the compaction pressure. Increasing compaction pressure led to higher sintering rate and lower sintering temperature. Increasing compaction pressure also led to decreasing linear shrinkage of the sintered bodies, from 24.54% of 50 MPa to 20.9% of 400 MPa. Compaction pressure showed only a weak influence on machinability of zirconia blanks, but the higher compaction pressure resulted in the poor surface quality.
  
  
  CONCLUSIONS
  The better sintering property and machinability of dental zirconia ceramic is found for 200-300 MPa compaction pressure.
authors.affiliation: Department of Prosthodontics, College of Stomatology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China. huanghui_68@126.com
authors.forename: Hui
authors.initials: H
authors.lastname: Huang
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
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: D002516:Ceramics; D003764:Dental Materials; D015040:Zirconium
chemical_list: D003764:Dental Materials; D015040:Zirconium; C028541:zirconium oxide