ASTM E2670-09

The light reflected from the teeth and emitted from the plaque on the teeth is captured by a DSC. Digital data extracted from the images can be used to discriminate and classify pixels. Monitored over time, changes in plaque coverage can be observed. An example is a clinical study of the efficacy of tooth brushes to remove dental plaque.

Assessing the quantity and coverage of dental plaque on teeth can be used to optimize the design of products and procedures intended to reduce dental plaque coverage.

Clinical assessment, for example, the modified Turesky Plaque Index, ^, is a subjective, non- linear, integer based scale that may require extensive examiner training and recertification. The method described here provides increased precision, repeatability, and reproducibility in comparison to other methods.

This procedure is suitable for use in research and development, marketing claims and advertising, comparative product analysis, and clinical trials.

1.1 This method covers the procedure, instrumental requirements, standardization procedures, material standards, measurement procedures, and parameters necessary to make precise measurements of dental plaque on the teeth revealed by fluorescence. In particular it is meant to measure the amount of plaque and plaque coverage on human teeth.

1.2 Digital images are used to measure the coverage of dental plaque on the teeth using discrimination analysis. All localized discoloration, such as stains, inclusions, pigmentations, etc., may be separated from the measurement and the analysis. All other non-relevant parts, such as teeth, tongue, spaces, dental restorations or prostheses, etc., must be separated from the measurement and the analysis.

Note 1—This procedure may not be applicable for all types of dental work.

1.3 The broadband reflectance factors of the teeth and surrounding tissue are measured. The colorimetric measurement is performed using an illuminator system that provides controlled illumination on the teeth and surrounding tissue. A Digital Still Camera (DSC) is used to capture the digital image.

1.4 Data acquired using this method may be used to assess personal plaque coverage for the purposes of identifying overall health status, health status at specific sites in the mouth, or to track changes in personal health status for individuals over time. Pooled data may be used to assess plaque coverage, health, disease among populations in epidemiological surveys, evaluation of comparative product efficacy, or safety and treatment response in clinical trials involving plaque coverage or disease.

1.5 The apparatus, measurement procedure, and analysis technique described herein are generic. The intent is not to exclude a specific apparatus, measurement procedure, or analysis technique.

1.6 The values stated in SI units are to be regarded as standard. The values in parenthesis are for information only.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.