title: [Clinical assessment of acceptability of shade mismatch of infiltrated alumina ceramic crowns].
abstract: OBJECTIVE
  To measure and evaluate the acceptability of shade mismatch of infiltrated alumina ceramic crowns directly in clinic.
  
  
  METHODS
  Ten cases with restoration of hot casting alumina ceramic crown were collected in clinic. L*, a*, b*, C, H, ΔE values of hot casting alumina ceramic crowns and corresponding natural teeth in natural light were surveyed and calculated, then analyzed with CIE1976L*a*b* color system, digital photography and Photoshop CS2. All statistical analyses and calculations were completed in paired t test with SAS6.12 software package.
  
  
  RESULTS
  In cervical 1/3 region, significant statistical difference in lightness, a*, hue angle parameter value between alumina all-ceramic crown and natural tooth (P<0.01) was found; in middle 1/3 region, significant difference in a*, b*, saturation parameter value (P<0.01) existed; in incisory 1/3 region, the parameters had no significant difference (P>0.05). To parameter ΔE, there was significant difference in every region, but it was in the acceptable range.
  
  
  CONCLUSIONS
  The acceptability of shade mismatch is about 6 ΔE units, we can analyse the color difference between the restoration and natural teeth directly in clinic through symmetry of central incisor.
authors.affiliation: Department of Prosthodontics, Shanghai Stomatological Disease Centre, Shanghai 200001, China. dongzhengjie@hotmail.com
authors.forename: Zheng-jie
authors.initials: ZJ
authors.lastname: Dong
authors.forename: Kan
authors.initials: K
authors.lastname: Xu
mesh_terms: D000537:Aluminum Oxide; D003116:Color; D003442:Crowns; D003776:Dental Porcelain; D006801:Humans; D017797:Prosthesis Coloring; D013053:Spectrophotometry; D019228:Tooth Crown
chemical_list: D003776:Dental Porcelain; D000537:Aluminum Oxide