title: Development of a stain shade guide to aid the measurement of extrinsic dental stain.
abstract: BACKGROUND
  Accurate and reproducible assessment of extrinsic staining is pivotal to determining efficacy of some tooth whitening oral hygiene products. The aim of this study was: (1) to produce a stain shade guide to aid the in vitro and in vivo stain assessment (2) to assess intra- and inter-examiner reproducibility of stain assessment using the stain shade guide.
  
  
  METHODS
  Using chlorhexidine and tea, perspex and acrylic teeth specimens were stained. The amount of staining on the perspex was measured with a spectrophotometer and the values obtained were assigned to the stained acrylic teeth, which were made into a stain guide. Using clinical photographs and a group of 10 volunteers, stain area and intensity were assessed using the stain guide and the recognized Lobene stain index by two examiners. The degree of intra- and inter-examiner reproducibility for these measurements were assessed using Cohen's kappa statistics.
  
  
  RESULTS
  For both the clinical examination and use of photographs, intra-examiner reproducibility for stain intensity was improved when using the stain guide compared with the Lobene Index. Similarly, when assessing inter-examiner reproducibility, stain intensity kappa values were greater using the stain guide (kappa = 0.82) compared with the Lobene Index (kappa = 0.57).
  
  
  CONCLUSIONS
  The findings of this study would suggest that the use of the stain guide could be of importance in the assessment of extrinsic dental stain.
authors.affiliation: Department of Oral and Dental Science, University of Bristol, Bristol, UK.
authors.forename: K
authors.initials: K
authors.lastname: Gadhia
authors.forename: R
authors.initials: R
authors.lastname: Shah
authors.forename: D
authors.initials: D
authors.lastname: Swaminathan
authors.forename: S
authors.initials: S
authors.lastname: Wetton
authors.forename: J
authors.initials: J
authors.lastname: Moran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003116:Color / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D023861:Photography, Dental; D015203:Reproducibility of Results; D014075:Tooth Discoloration / Q000139:chemically induced / Q000175:diagnosis*; D014093:Tooth, Artificial