title: Proposed shade guide for attached gingiva--a pilot study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of race, age, and gender on Commision Internationale de l'Eclairage Lab color space (CIELAB) values of attached gingival colors. The color coordinates of an optimal proposed attached gingival shade guide were also determined.
  
  
  METHODS
  Participants (n = 120) were recruited to fulfill the following stratification of five age groups: 18-29, 30-39, 40-49, 50-59, and 60-85, with four racial categories (white, black, Asian, and others) and balanced for gender. Reflectance measurements of participants' attached gingiva were made using a spectroradiometer and Xenon arc lamp with a 45/0 optical configuration. A stepwise discriminant analysis was carried out to identify gingival color contribution from race, age, and gender. A hierarchical clustering analysis was used to identify color groups that clustered together. The coverage error of the proposed shade guide was calculated to the original gingival color.
  
  
  RESULTS
  The stepwise discriminant analysis showed a statistically significant difference in gingival color contribution from the factors evaluated. Significant influence was found for the race/gender factors (p < 0.05), but not for age. The cluster analysis results revealed three cluster centroids with mean L*a*b* as follows: (1 = 51.0 ± 4.2, 27.7 ± 4.7, 18.3 ± 3.2), (2 = 61.4 ± 4.5, 24.3 ± 4.3, 17.6 ± 2.3), and (3 = 36.1 ± 4.1, 21 ± 4.9, 16 ± 5.2). The coverage errors to the following racial categories were: Asian (ΔE = 6.0 ± 4.8), black (ΔE = 6.7 ± 3.9), others (ΔE = 5.8 ± 2.9), and white (ΔE = 4.6 ± 2.7).
  
  
  CONCLUSIONS
  The study showed that L*a*b* was significantly affected by race and gender. Clustering analysis was able to identify clusters in 120 participants for three gingival tones.
authors: Assistant Professor, Department of Removable Prosthodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan; Formerly Visiting Assistant Professor, Department of Periodontics, Creighton University School of Dentistry, Omaha, NE.
authors: Masayasu
authors: M
authors: Ito
authors: David B
authors: DB
authors: Marx
authors: Ansgar C
authors: AC
authors: Cheng
authors: Alvin G
authors: AG
authors: Wee
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016000:Cluster Analysis; D003116:Color / Q000592:standards; D003124:Colorimetry / Q000295:instrumentation* / Q000592:standards*; D003710:Demography; D005260:Female; D005881:Gingiva / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D044469:Racial Groups / Q000208:ethnology; D012015:Reference Standards; D012016:Reference Values; D012737:Sex Factors
keywords: Gingiva color; acrylic; pink porcelain