title: A photographic method to measure the colour characteristics of healthy gingiva.
abstract: BACKGROUND
  Colour of healthy gingiva is mostly determined by subjective visual observation. The introduction of digital imaging and diagnostic tools to evaluate colour makes it feasible to measure gingival colour more objectively.
  
  
  METHODS
  A study was designed to obtain reproducible photographs of anterior maxillary gingiva of a study group of 26 dental hygienist students with a professional attitude for healthy gingiva. Gingival health was evaluated clinically by probing marginal portions of gingiva. No bleeding on probing was considered the gold standard for health. For the colour measurements on the photographs adobe photoshop software was used and colour was expressed in the Cie L*a*b* colour system. Gingival selections were extracted from the photographs and brightness (L*), redness (a*) and yellowness (b*) were calculated.
  
  
  RESULTS
  The L* colour characteristic varied from 72 to 78 (average 76), The a* characteristic from 12 to 23 (average 20) and the b* characteristic from 13 to 21 (average 16).
  
  
  CONCLUSIONS
  The findings of this study suggest that the colour characteristics of normal gingiva can vary considerably and still be healthy. Objective digital measurements of gingival colour characteristics may become a valuable, reproducible and practicable evaluation method of gingival health. This photographic study has explored measurement procedures towards this aim.
authors.affiliation: Academic Centre for Dentistry Amsterdam (ACTA), Free University and University of Amsterdam, Amsterdam, The Netherlands. h.denissen@acta.nl
authors.forename: H
authors.initials: H
authors.lastname: Denissen
authors.forename: A
authors.initials: A
authors.lastname: Kuijkens
authors.forename: A
authors.initials: A
authors.lastname: Dozić
mesh_terms: D000328:Adult; D003116:Color; D003124:Colorimetry / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D005881:Gingiva / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D023861:Photography, Dental / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results