Dental Biofilms: Detection and Quantification of Plaque - Instructions for Students

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Dental Biofilms: Detection and Quantification of Plaque

Supplies Needed:

1 dental plaque disclosing agent such as Trace Disclosing Tablets
1 Quigley Hein plaque index (given below)


Chew a Trace Disclosing Tablet

Estimating the amount of plaque

This index evaluates the plaque revealed on the cheek (buccal) side and the tongue (lingual) side of the teeth on a scale from 0 - 5 where:

The Quigley Hein plaque index

0 = no plaque
1 = isolated flecks of plaque near the gingival (gum) margin
2 = a 1 mm band of plaque at the gingival margin
3 = up to 1/3 of the surface covered with plaque
4 = disclosed plaque from 1/3 to 2/3 of the surface
5 = disclosed plaque on more than 2/3 of the surface


Trace Disclosing Tablets
Figure 1.  Dental Disclosing Tablets
Photo credit: D. Williams

After chewing a Trace Disclosing Tablet, plaque on teeth can be easily seen.

After chewing a Disclosing Tablet
Figure 2.  Teeth showing plaque stained by tablet. Photo credit: D. Williams

Educational Program Curricula and Teaching Resources

Supported in part by the Waksman Foundation for Microbiology
Developed in collaboration with Dr. John Lennox, Education Editor, Penn State Altoona
© 1999-2008 Center for Biofilm Engineering,