title: Optical effects of different colors of artificial gingiva on ceramic crowns.
abstract: OBJECTIVE
  The interaction between gingival color and the shade of ceramic restorations has never been fully studied. The purpose of this study is to investigate the optical effects of altering artificial gingival color on the ceramic crown shade in the cervical area.
  
  
  METHODS
  Thirty-one all-ceramic crowns of different shades were used in this study with six different artificial gingival colors. Using a spectrophotometer (Crystaleye(®) Olympus, Japan), we measured the shade of crowns in cervical areas with each of six different artificial gingiva. The crown color measured in the presence of pink artificial gingiva (control) was compared with the crown color with five other artificial gingiva. color difference values ΔE* were calculated and compared between the control group and test groups and the correlation of the artificial gingival color with the crown color was also assessed.
  
  
  RESULTS
  Significant differences were found in the mean L* and a* values of all-ceramic crowns at the cervical regions in all six gingival color groups (p<0.001) and significant Pearson correlations were also found for the mean L* (r=0.987, p<0.001) and a* (r=0.856, p=0.03) values between the artificial gingiva and the ceramic crowns. The mean ΔE* values between the control group and each of the five other gingival groups were all significantly larger than the clinical perceptual threshold of ΔE* 1.6 (p<0.001).
  
  
  CONCLUSIONS
  Different colors of artificial gingiva generated clinically detectable shade differences in the cervical region of ceramic crowns.
authors: Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA, United States.
authors: Jian
authors: J
authors: Wang
authors: Jin
authors: J
authors: Lin
authors: Mindy
authors: M
authors: Gil
authors: John D
authors: JD
authors: Da Silva
authors: Robert
authors: R
authors: Wright
authors: Shigemi
authors: S
authors: Ishikawa-Nagai
mesh_terms: D000465:Algorithms; D003116:Color; D003442:Crowns; D003776:Dental Porcelain / Q000737:chemistry*; D005881:Gingiva; D010515:Periodontal Prosthesis; D017797:Prosthesis Coloring; D012684:Sensory Thresholds / Q000502:physiology; D013053:Spectrophotometry / Q000295:instrumentation; D014796:Visual Perception / Q000502:physiology; D015040:Zirconium / Q000737:chemistry
chemical_list: D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide
keywords: Aesthetics; Ceramic crown; Color; Gingiva