title: Clinical attachment loss: estimation by direct and indirect methods.
abstract: OBJECTIVE
  This observational study aimed to compare the estimation of clinical attachment loss (CAL) as measured by direct (CALD ) and indirect (CALI ) methods.
  
  
  METHODS
  Periodontitis patients (n = 75; mean age: 50.9 ± 8.02 years; 72.2% women; 50.6% smokers) received a periodontal examination (six sites/tooth) to determine the presence of visible plaque and calculus, the gingival bleeding index (GBI), periodontal probing depth (PPD), bleeding on probing (BOP), CALD and gingival recession (GR). CALI values resulted from the sum of PPD and GR values. Statistical analysis considered only data from sites with visible GR (e.g. the gingival margin apical to the cemento-enamel junction; n = 4,757 sites) and determined the mean difference between CALI and CALD measurements. Based on the mean difference, univariate and multivariate analyses were also performed.
  
  
  RESULTS
  Mean CALD and CALI values were 3.96 ± 2.07 mm and 4.47 ± 2.03 mm, respectively. The indirect method overestimated CAL compared with the direct method (mean difference: 0.51 ± 1.23 mm; P < 0.001). On uni- and multivariate analyses, absence of GBI and BOP, PPD and proximal site location had significant influences on the overestimation of CAL by the indirect method (all P ≤ 0.01). The indirect method increased the CAL value by 0.38 mm for each additional 1 mm in PPD.
  
  
  CONCLUSIONS
  To decrease the number of probing errors in daily practice it is suggested that direct examination is more appropriate than the indirect method for estimating CAL.
authors: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors: Viviane Leal
authors: VL
authors: Barbosa
authors: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors: Patricia D Melchiors
authors: http://orcid.org/0000-0001-8846-9177
authors: PD
authors: Angst
authors: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors: Amanda
authors: A
authors: Finger Stadler
authors: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors: Rui V
authors: RV
authors: Oppermann
authors: Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors: Sabrina Carvalho
authors: SC
authors: Gomes
mesh_terms: D003773:Dental Plaque / Q000175:diagnosis; D003774:Dental Plaque Index; D005260:Female; D005884:Gingival Hemorrhage / Q000175:diagnosis; D005889:Gingival Recession / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000175:diagnosis*; D010512:Periodontal Index
keywords: Periodontal disease; dental practice; diagnosis