title: [Crown color match of implant-supported zirconia and porcelain-fused-to-metal restorations: a spectrophotometric comparison].
abstract: OBJECTIVE
  This study aimed to compare the crown color match of implant-supported zirconia restorations and porcelain-fused-to-metal (PFM) restorations in the anterior maxillary region through spectrophotometric evaluation.
  
  
  METHODS
  Eighteen patients with 29 implant-supported single crowns in the anterior maxillary area were recruited. Eleven of the implant crowns were zirconia restorations and 18 were PFM restorations. Color matching of the implant crown with contra-lateral/ neighboring tooth at the position of body 1/3 of the crown was assessed using a spectrophotometer (SpectroShade) in CIE L* a* b* coordinates. Subjective crown color match scores were evaluated. Independent sample t test of SPSS 17.0 was used to compare the difference between zirconia restoration and PFM restoration. Spearman correlation was used to analyze the relationship between the spectrophotometric color difference and the subjective crown color match score. Descriptive statistics was used to analyze the distribution of color coordinates of natural anterial teeth.
  
  
  RESULTS
  The crown color of the implant-supported zirconia restorations and PFM restorations were both lighter than that of natural teeth (delta L, 4.5 +/- 3.2, 1.0 +/- 2.6). The lightness difference induced by zirconia restorations was significantly larger than that induced by PFM restorations (P=0.004). The spectrophotometric crown color difference (delta E) induced by zirconia restorations (7.0 +/- 2.8) was significantly larger than that induced by PFM restorations (4.0 +/- 1.9) (P=0.002), and both values were beyond the clinical thresholds (3.7).
  
  
  CONCLUSIONS
  The spectrophotometric crown color difference induced by zirconia restorations was significantly larger than that induced by PFM restorations. However, they were indistinguishable in subjective evaluation.
authors.forename: Min
authors.initials: M
authors.lastname: Peng
authors.forename: Wei
authors.initials: W
authors.lastname: Fei
authors.forename: Mandana
authors.initials: M
authors.lastname: Hosseini
authors.forename: Klaus
authors.initials: K
authors.lastname: Gotfredsen
mesh_terms: D003116:Color; D003442:Crowns; D003776:Dental Porcelain; D006801:Humans; D013053:Spectrophotometry; D014070:Tooth; D015040:Zirconium
chemical_list: D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide