ASTM_E_2670_-_15.pdf

Designation:E267015Standard Test Method forObjective Quantification of Dental Plaque Using Digital StillCameras1This standard is issued under the fixed designation E2670;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONDental plaque is a biofilm,which grows on teeth and surrounding tissue.In many cases,dentalplaque is the underlying cause of many oral diseases,that is,cavities and gum diseases.Thus,controlling dental plaque through its removal and inhibition of re-growth is essential to maintaininggood oral health.Today,there are hundreds of products produced to control dental plaque.Examplesare;toothbrushes,toothpastes,floss,rinses,gums and routine dental cleanings.One universal designobjective maximizes plaque control through enhanced cleaning ability or chemistry which inhibitsplaque growth;that is,anti-bacterial agents.Often,the effectiveness of a product or procedure ismeasured in a clinical trial with traditional methods of estimating plaque coverage.For example,themodified Turesky index is often used.This index is an integer scale ranging from 0(no plaque)to 5(complete plaque coverage).The clinical examiner estimates the numerical value or score based onvisual observation of the plaque.Unfortunately,there are drawbacks to this approach.First,the scaleis non-linear with respect to plaque area coverage.Second,the application of the scale is subjectiveby nature.Therefore,an objective method of measuring the amount of plaque on teeth represents asignificant improvement in the science of plaque measurement.1.Scope1.1 This method covers the procedure,instrumentalrequirements,standardization procedures,material standards,measurement procedures,and parameters necessary to makeprecise measurements of dental plaque on the teeth revealed byfluorescence.In particular it is meant to measure the amount ofplaque and plaque coverage on human teeth.1.2 Digital images are used to measure the coverage ofdental plaque on the teeth using discrimination analysis.Alllocalizeddiscoloration,suchasstains,inclusions,pigmentations,etc.,may be separated from the measurementand the analysis.All other non-relevant parts,such as teeth,tongue,spaces,dental restorations or prostheses,etc.,must beseparated from the measurement and the analysis.NOTE1This procedure may not be applicable for all types of dentalwork.1.3 The broadband reflectance factors of the teeth andsurrounding tissue are measured.The colorimetric measure-ment is performed using an illuminator system that providescontrolled illumination on the teeth and surrounding tissue.ADigital Still Camera(DSC)is used to capture the digital image.1.4 Data acquired using this method may be used to assesspersonal plaque coverage for the purposes of identifyingoverall health status,health status at specific sites in the mouth,or to track changes in personal health status for individualsover time.Pooled data may be used to assess plaque coverage,health,disease among populations in epidemiological surveys,evaluation of comparative product efficacy,or safety andtreatment response in clinical trials involving plaque coverageor disease.1.5 The apparatus,measurement procedure,and analysistechnique described herein are generic.The intent is not toexclude a specific apparatus,measurement procedure,or analy-sis technique.1.6 The values stated in SI units are to be regarded asstandard.The values in parenthesis are for information only.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1This test method is under the jurisdiction of ASTM Committee E12 on ColorandAppearance and is the direct responsibility of Subcommittee E12.06 on Display,Imaging and Imaging Colorimetry.Current edition approved July 1,2015.Published August 2015.Originallyapproved in 2009.Last previous edition approved in 2009 as E2670 09.DOI:10.1520/E2670-15.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 2.Referenced Documents2.1 ASTM Standards:2E179 Guide for Selection of Geometric Conditions forMeasurement of Reflection and Transmission Propertiesof MaterialsE284 Terminology of AppearanceE1345 Practice for Reducing the Effect of Variability ofColor Measurement by Use of Multiple MeasurementsE1767 Practice for Specifying the Geometries of Observa-tion and Measurement to Characterize the Appearance ofMaterials2.2 ISO Publications:3ISO 17321-1 Colour characterization of digital still cameras(DSCs)Part 1:stimuli,metrology,and test proceduresISO/IEC 15444-1:2000JPEG2000 Information technology