title: [Influence of all-ceramic and porcelain-fused-to-metal restorations on peri-implant gingival discoloration:a spectrophotometric comparison].
abstract: OBJECTIVE
  To compare the gingival discoloration of implant supported all-ceramic and porcelain-fused-to-metal (PFM) restorations in anterior maxillary region by spectrophotometric evaluation.
  
  
  METHODS
  Eighteen patients with 29 implant-supported single crowns (11 all-ceramic restorations, 9 PFM restorations with titanium abutment and 9 PFM restorations with golden alloy abutment) in anterior maxillary area were recruited. The color difference between peri-implant gingiva and contra-lateral/neighboring mucosa was assessed using a spectrophotometer in CIELab coordinates. Subjective gingival discoloration scores were evaluated by clinician. SPSS17.0 software package was used to analyze the data.
  
  
  RESULTS
  There was no significant difference between all-ceramic group (3.4±1.8) and PFM group (4.9±3.4) spectrophotometrically. No significant difference was found between all-ceramic restorations and PFM restorations with titanium abutment (3.5±2.5), and no significant difference was found between PFM restorations with titanium abutment and PFM restorations with gold alloy abutment (6.3±3.8) either. There was, however, significant difference between all-ceramic restorations and PFM restorations with gold alloy abutment (P=0.037). There was no significant difference between all-ceramic group and PFM group regarding the clinical gingival discoloration score (GDS), and this gingival discoloration score was found to have significant correlation with the spectrophotometric evaluation (rs=0.426, P=0.021).
  
  
  CONCLUSIONS
  There is no significant difference between all-ceramic group and PFM group as regard to both spectrophotometric and clinical evaluation of gingival discoloration, but the PFM restorations with gold alloy abutment induce significantly higher discoloration than all-ceramic restorations.
authors.affiliation: Department of Dentistry, Medical Academy of Sichuan Province, Sichuan Province, China.
authors.forename: Min
authors.initials: M
authors.lastname: Peng
authors.forename: Wei
authors.initials: W
authors.lastname: Fei
authors.forename: Hosseini
authors.initials: H
authors.lastname: Mandana
authors.forename: Gotfredsen
authors.initials: G
authors.lastname: Klaus
mesh_terms: D002516:Ceramics; D003442:Crowns; D000044:Dental Abutments; D003776:Dental Porcelain; D005881:Gingiva; D006801:Humans; D008670:Metals; D013053:Spectrophotometry; D014025:Titanium; D014070:Tooth
chemical_list: D008670:Metals; D003776:Dental Porcelain; D014025:Titanium