ISO/TR TECHNICAL REPORT 28642 Second edition 2016-12-01 Dentistry Guidance on colour measurement Médecine bucco-dentaire - Directives relatives au mesurage de la couleur Reference number IS0/TR 28642:2016(E) ISO International Organization for Standardization @IS02016 vided by IHS under No reproduction or networking permitted without license from IHS IS0/TR 28642:2016(E) COPYRIGHT PROTECTED DOCUMENT IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org No reproduction or networking permited withoutlicense from IHS IS0/TR 28642:2016(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms and definitions ..1 4 Visual and instrumental colour assessment .3 4.1 Devices .3 4.2 Setting ..4 4.2.1 Illuminant .4 4.2.2 Standard observer ..4 4.2.3 Geometric conditions. 4 4.2.4 Illuminance .4 4.2.5 Visual angle of subtense ..4 4.2.6 Background. ..4 4.2.7 Surround 4 4.2.8 Additional/other considerations ..5 5 Observers ..5 5.1 Evaluation of colour competency of candidate for observer in studies on acceptability or perceptibility in dentistry .5 5.1.1 Ishihara colour blindness test... 5.1.2 Farnsworth-Munsell 100 hue test .5 5.1.3 Test for colour discrimination competency in dentistry 5.2 Guidelines for observer selection for acceptability or perceptibility evaluation in dentistry ..5 5.2.1 Generaltests ..5 5.2.2 Test for colour discrimination competency in dentistry ..5 5.2.3 Testing intervals for qualified observers. .6 6 Testing of acceptability and perceptibility thresholds .6 6.1 Tissues and materials to be tested for perceptibility and acceptability thresholds ..6 6.2 Test methods. .6 6.2.1 Visual judgments .6 6.2.2 Instrumentalevaluation ..6 7 Application and interpretation .6 7.1 Colour compatibility .7 7.1.1 Colour compatibility between dental material and human tissues 7.1.2 Colour compatibility between dental materials 1 7.1.3 Coverage error of dental shade guides .. 7 7.2 Colour stability. 7 7.2.1 Colour stability during fabrication/at placement. 7 7.2.2 Colour stability after aging and staining[12] 7.3 Colour interactions. .7 7.3.1 Colour shifting of aesthetic restorative materials[13][14] .7 7.3.2 Masking potential of opaque materials. .8 8 Reporting of colour and colour difference assessment ..8 8.1 Illuminant .8 8.2 Object. ..8 8.3 Observer/instrument 8.3.1 Observer. ..8 8.3.2 Instrument .9 Bibliography ..10 iii vithout license from IHS