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Updated: Aug 8, 2026
Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision
Published on: April 29, 2014
Comparison of a conventional and modified tooth stain index
L M Macpherson1, K W Stephen, A Joiner
1Dental Public Health Unit, University of Glasgow Dental School, UK. l.macpherson@dental.gla.ac.uk
Objectives:
To evaluate a modified tooth stain index and determine the effect of dietary factors on stain formation.
Methods:
At baseline, 182 adult volunteers were given a full oral prophylaxis followed by stain assessment using a modification of the Lobene index. This involved assigning separate scores to the mesial (M) and distal (D) sites of each tooth, in addition to the standard gingival area (G) and tooth body (B). For each site, stain intensity and areas were scored. The sum of (intensity X area) scores was calculated for all sites (GBMD-value) and for the gingival and body sites only (GB-value). The subjects used a standard abrasive dentifrice and a soft toothbrush for 6 weeks.
Results:
Stain was reassessed and the average increase in GBMD-value was 20.9 (sd=9.9) (buccal aspect) and 29.9 (sd=18.0) (lingual aspect). The corresponding GB-values were 4.4 (sd=4.8) and 12.5 (sd=10.2). The coefficients of variation of the GBMD index values were consistently lower than those of the GB values. Smoking and tea-drinking were found to be the only significant (p<0.001) factors investigated for stain formation.
Conclusions:
It is concluded that the modified index may well be advantageous to its conventional counterpart because sites with most visible stain are assessed separately and because it may also offer higher discriminatory power due to a lower coefficient of variation.
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