ASTM E2466-13

Standard Test Method for Colorimetry of Teeth Using Digital Still Camera Technology (Withdrawn 2018)

SIGNIFICANCE AND USE
5.1 The light reflected from the facial anterior teeth can be used to calculate color coordinates. Monitored over time, changes in color can be observed. These data reveal information about the efficacy of a product, treatment study, or epidemiology of tooth color. For example, clinical studies of consumer tooth whitening systems evaluate the efficacy of manufacturers’ products.  
5.2 The change in color of the facial surfaces of anterior teeth can be used to optimize the efficacy of tooth whitening systems. For example, the data can provide the answer the question: “What is the optimum percentage of whitening agent in a consumer tooth whitening system?”  
5.3 This procedure is suitable for use in research and development, marketing studies, comparative product analyses, and clinical trials.  
5.4 Prior research shows that a popular visual assessment method of determining tooth color, changes in tooth color, and whiteness among clinicians yields less than desirable results (1-4). These assessment tools are designated “shade guides.” They consist of tooth-shaped, synthetic objects in the form of teeth all of slightly different colors or different shades from one another. A “shade” is generally regarded as a color slightly different from a reference color (on a comparative basis). The colors of the synthetic teeth in these “shade guides” do not progress linearly as observed visually or logically in a CIE colorimetric coordinate system,5 and they are metameric to real teeth.  
5.5 Translucency—Human teeth are translucent and the degree of translucency varies widely between subjects. However, translucency does not vary over the short term and is not therefore a consideration in this test method.
SCOPE
1.1 This test method covers the procedure, instrumental requirements, standardization procedures, material standards, measurement procedures, and parameters necessary to make precise measurements of in-vivo tooth color and tooth whiteness. In particular it is meant to measure the color of teeth in selected human subjects.  
1.2 Digital images are used to evaluate tooth color of both posterior and anterior dentition (teeth). All other non-relevant parts, such as gums, spaces, etc., must be separated from the measurement and the analysis. All localized discoloration; such as stains, inclusions, etc., may be separated from the measurement and the analysis.  
1.3 The broadband reflectance factors of teeth are measured. The colorimetric measurement is performed with a digital still camera while using an illuminator(s) that provides controlled illumination on the teeth. The measured data from a digital image are captured using a DSC. This test method is particularly useful for the gamut of tooth color which is:  
1.3.1 CIE L* from 55 to 95,  
1.3.2 CIE a* from 3 to 12,  
1.3.3 CIE b* from 8 to 25 units.  
1.4 The wavelengths for this test method include that portion of the visible spectrum from 400 to 700 nm.  
1.5 Data acquired using this test method is for comparative purposes used during clinical trials or other types of research.  
1.6 This test method is designed to encompass natural teeth, artificial teeth, restorations, and shade guides.Note 1—This procedure may not be applicable for all types of dental work.  
1.7 The apparatus, measurement procedure, data analysis technique are generic, so that a specific apparatus, measurement procedure, or data analysis technique may not be excluded.  
1.8 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.9 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 to determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
This test method covers the procedure, instrumental require...

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-2012
• Withdrawal Date: 03-May-2018
• ICS: 11.060.01 - Dentistry in general
• Technical Committee: E12 - Color and Appearance
• Drafting Committee: E12.06 - Display, Imaging and Imaging Colorimetry

Relations

• Replaces: ASTM E2466-06(2011) - Standard Test Method for Colorimetry of Teeth Using Digital Still Camera Technology
• Effective Date: 01-Jan-2013

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2466 − 13
Standard Test Method for
1
Colorimetry of Teeth Using Digital Still Camera Technology
This standard is issued under the fixed designation E2466; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
Tooth color is an important parameter used to ascertain certain medical and esthetic information.
CIE colorimetric values for the teeth are derived from the native RGB signals generated by a digital
stillcamera,DSC,bybroadbandmeasurementofthereflectanceofteeth.Theilluminationangleis45
degrees and CIELAB colorimetric coordinates are computed using equations contained in Practice
E308. This test method, E2466, specifies the procedure used for the measurement of tooth color
in-vivo and in-vitro with illumination at 45 degrees relative to the sample plane which is also the
normalofthemouth,underanapproximateequalenergyspectrum.Thistestmethodisappropriatefor
anterior and posterior teeth.
1. Scope 1.5 Data acquired using this test method is for comparative
purposes used during clinical trials or other types of research.
1.1 This test method covers the procedure, instrumental
1.6 Thistestmethodisdesignedtoencompassnaturalteeth,
requirements, standardization procedures, material standards,
artificial teeth, restorations, and shade guides.
measurement procedures, and parameters necessary to make
precise measurements of in-vivo tooth color and tooth white-
NOTE 1—This procedure may not be applicable for all types of dental
ness. In particular it is meant to measure the color of teeth in
work.
selected human subjects.
1.7 The apparatus, measurement procedure, data analysis
1.2 Digital images are used to evaluate tooth color of both technique are generic, so that a specific apparatus, measure-
posterior and anterior dentition (teeth). All other non-relevant ment procedure, or data analysis technique may not be ex-
parts, such as gums, spaces, etc., must be separated from the cluded.
measurementandtheanalysis.Alllocalizeddiscoloration;such
1.8 The values stated in SI units are to be regarded as the
as stains, inclusions, etc., may be separated from the measure-
standard. The values given in parentheses are for information
ment and the analysis.
only.
1.3 Thebroadbandreflectancefactorsofteetharemeasured.
1.9 This standard does not purport to address all of the
The colorimetric measurement is performed with a digital still
safety concerns, if any, associated with its use. It is the
camera while using an illuminator(s) that provides controlled
responsibility of the user of this standard to establish appro-
illumination on the teeth. The measured data from a digital
priate safety and health practices and to determine the
image are captured using a DSC. This test method is particu-
applicability of regulatory limitations prior to use.
larly useful for the gamut of tooth color which is:
2. Referenced Documents
1.3.1 CIE L* from 55 to 95,
2
1.3.2 CIE a* from 3 to 12, 2.1 ASTM Standards:
D2244Practice for Calculation of Color Tolerances and
1.3.3 CIE b* from 8 to 25 units.
Color Differences from Instrumentally Measured Color
1.4 The wavelengths for this test method include that
Coordinates
portion of the visible spectrum from 400 to 700 nm.
E179Guide for Selection of Geometric Conditions for
Measurement of Reflection and Transmission Properties
of Materials
1
This test method is under the jurisdiction of ASTM Committee E12 on Color
andAppearanceandisthedirectresponsibilityofSubcommitteeE12.06onDisplay,
2
Imaging and Imaging Colorimetry. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Jan. 1, 2013. Published January 2013. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2006. Last previous edition approved in 2011 as E2466– 06 (2011). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/E2466-13. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E2466 − 13
E284Terminology of Appearance 3.2.10 native digital still camera spectral response function,
E308PracticeforComputingtheColorsofObjectsbyUsing n—thefunctionrelatingsceneradiancetoimageintensityofan
the CIE System
imaging system is called the digital still camera spectral
E313Practice for Calculating Yellowness and Whiteness
response function.
Indices from Instrumentally Measured Color Coordinates
3.2.11 polarization, n—the orientation of the vibration pat-
E1345Practice for R
...