title: Spectrophotometric analysis of clinical factors related to the color of ceramic restorations: A pilot study.
abstract: BACKGROUND
  Shade matching natural teeth with ceramic restorations is still an esthetic, clinical challenge.
  
  
  OBJECTIVE
  The purpose of this prospective clinical study was to evaluate the influence of color-related factors on the color variation of ceramic restorations based on spectrophotometric analysis.
  
  
  METHODS
  Color records were obtained from 11 participants who received 38 lithium disilicate restorations. CIELab color coordinates were measured with a spectrophotometer on the ceramic restoration, tooth (baseline), prepared tooth, and luted ceramics. Color variation (ΔE00) was calculated for each variable (luting agent and restoration type, tooth substrate shade, ceramic thickness, and translucency parameters) measured at baseline on the prepared tooth and after cementation of the restorations. Confidence intervals (CI) for the means (95% CI) were calculated, and the ΔE00values and CIELab individual color coordinates were compared for each pair of variable by using the Student t test or Welch test (α=.05).
  
  
  RESULTS
  Greater color variation values were observed between measurements obtained on the prepared tooth and luted restoration. The lower ΔE00values were observed over darker tooth substrate measured at baseline and after luting (P=.007).
  
  
  CONCLUSIONS
  The 3 conditions evaluated presented clinically visible color differences, highlighting the importance of clinical evaluations on the visual color acceptability limits for restorations, which are usually defined in laboratory studies. The lithium disilicate ceramic showed lower masking ability over darker tooth substrate, whereas the coordinates L*, a*, and b* were cementation-dependent.
authors.affiliation: Doctoral student, Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Perroni
authors.affiliation: Professor, Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: César D
authors.initials: CD
authors.lastname: Bergoli
authors.affiliation: Professor, Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Mateus Bertolini F
authors.initials: MBF
authors.lastname: Dos Santos
authors.affiliation: Professor, Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Rafael R
authors.initials: RR
authors.lastname: Moraes
authors.affiliation: Professor, Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil. Electronic address: noeliboscato@gmail.com.
authors.forename: Noéli
authors.initials: N
authors.lastname: Boscato
mesh_terms: D000328:Adult; D002516:Ceramics / Q000627:therapeutic use*; D003116:Color; D003776:Dental Porcelain / Q000627:therapeutic use; D003793:Dental Restoration, Permanent / Q000379:methods; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D008297:Male; D010865:Pilot Projects; D011446:Prospective Studies; D013053:Spectrophotometry
chemical_list: C493120:lithia disilicate; D003776:Dental Porcelain