ISO INTERNATIONAL STANDARD 7491 Secondedition 2000-09-01 Dental materials --- Determination of colour stability Produits dentaires-Determination de la stabilite de couleur Referencenumber ISO7491:2000(E) ISO ?ISO2000 ISO7491:2000(E) PDFdisclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's ficensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer perfoming the editing. tn downloading this file,parties accept therein the responsibility of not intringing Adobe's ficensing policy.The So Central Secretariat accepts no liability in this area AdobeisatrademarkofAdobeSystemsIncorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unikely event that a problem relating to it is found, please infom the Central Secretariat at the address given beiow. 1SO2000 All rignhts reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any fom or by any means, electronic inthecountryoftherequester. ISOcopyrightoffice Casepostale56.CH-1211Geneva20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 [email protected] Web www.iso.ch Printed in Switzerland 1SO7491:2000(E) Foreword Iso (the Internationa! Organization for Standardization) is a worldwide federation of national standards bodies (Iso member bodies). The work of preparing international Standards is normally carried out through iso technical committees. Each member body interested in a subject for which a technica! committee has been established has liaison with Iso, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEc Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. patent rights. iso shall not be held responsible for identifying any or all such patent rights. Sc2,Prosthodonticmaterials. This second edition cancels and replaces the first edition (Iso 7491:1985), which has been technically revised. Iso2000All rights reserved ii IS07491:2000(E) Introduction Colour stability is an important characteristic of dental materials and it is expected that the test methods in this Intemational Standard will be referred to in the International Standards specifying such materials. iv iso2000-Allrightsreserved INTERNATIONAL STANDARD ISO 7491:2000(E) Dental materials - Determination of colour stability Scope This International Standard specifies a method for the determination of the colour stability of dental materials after exposure to light and water. 2 Normative references The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to. applies. Members of Iso and IEc maintain registers of currentlyvalid International Standards. Iso 3696, Water for analytical laboratory use --Specification and test methods. Iso 4892-2, Plastics -Methods of exposure to laboratory light sources -Part 2: Xenon-arc sources. CiE Pubfication 15.2, Colorimetry. 3 Test methods 3.1 Apparatus 3.1.1 Radiation source Xenon medium-pressure lamp with a colour temperature of 5 000 K to 10 o0o K and with an i