1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN ISO 7491:2000 The E
2、uropean Standard EN ISO 7491:2000 has the status of a British Standard ICS 11.060.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Dental materials Determination of colour stabilityThis British Standard, having been prepared under the direction of the Health and Environment
3、Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 December 2000 BSI 12-2000 ISBN 0 580 36612 X BS EN ISO 7491:2000 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard is the official English langu
4、age version of EN ISO 7491:2000. It is identical with ISO 7491:2000. It supersedes BS 6790:1987 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CH/51, Prosthodontic materials, which has the responsibility to: aid enquirers to understand the text; pres
5、ent to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can b
6、e obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The British Standards which implement intern
7、ational or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to inclu
8、de all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN
9、 ISO title page, the EN ISO foreword page, the ISO title page, pages ii to iv, pages 1 to 4, the annex ZA page and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.EUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO7491 September2000 ICS0
10、1.006.10 SupersedesEN27491:1991 Englishversion DentalmaterialsDeterminationofcolourstability(ISO 7491:2000) ProduitsdentairesDterminationdelastabilitdecouleur (ISO7491:2000) ZahnrztlicheWerkstoffeBestimmungder Farbbestndigkeit(ISO7491:2000) ThisEuropeanStandardwasapprovedbyCENon1September2000. CENme
11、mbersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENme
12、mber. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,
13、Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG CentralSecretariat:ruedeStassart,36B1050Brus
14、sels 2000CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO7491:2000EForeword Thetextof theInternationalStandardISO7491:2000hasbeenpreparedb y TechnicalCo mmittee ISO/TC106“Dentistr y“incollaborationwith TechnicalCo mmitteeCEN/ TC55“Dentistr y“,the
15、 secretariatofwhichisheldb yDIN. ThisEuropeanStandardsupersedesEN27491:1991. ThisEuropeanStandardshallbegiventhestatusof anationalstandard,eitherb ypublicationof an identicaltextorb yendorse ment,atthelatestb yMarch2001,andcon flictingnationalstandardsshall bewithdrawnatthelatestb yMarch2001. Accord
16、ingtotheCEN/CENELECInternalRegulations,thenationalstandardsorgani zationsofthe followingcountriesareboundtoi mplementthisEuropeanStandard:Austria,Belgiu m,C zechRepublic, Denmark,Finland,France,Ger many,Greece,Iceland,Ireland,Ital y,Luxe mbourg,Netherlands, Norway,Portugal,Spain,Sweden,Swit zerlanda
17、ndtheUnitedKingdo m. Endorsementnotice Thetextof theInternationalStandardISO7491:2000wasapprovedb yCENasaEuropeanStandard withoutan y modification. NOTE:Nor mativere ferencestoInternationalStandardsarelistedinannexZA(nor mative). ENISO7491:2000Referencenumber ISO7491:2000(E) INTERNATIONAL STANDARD I
18、SO 7491 Secondedition 2000-09-01 DentalmaterialsDeterminationofcolour stability ProduitsdentairesDterminationdelastabilitdecouleur ENISO7491:2000ii ENISO7491:2000 iii Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).Thework
19、ofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,in liaisonwithISO,alsotakepartinthe
20、work.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberb
21、odiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthisInternationalStandardmaybethesubjectof patentrights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights. Internatio
22、nalStandardISO7491waspreparedbyTechnicalCommitteeISO/TC106,Dentistry,Subcommittee SC2,Prosthodonticmaterials. Thissecondeditioncancelsandreplacesthefirstedition(ISO7491:1985),whichhasbeentechnicallyrevised. ENISO7491:2000iv Introduction Colourstabilityisanimportantcharacteristicofdentalmaterialsandi
23、tisexpectedthatthetestmethodsinthis InternationalStandardwillbereferredtointheInternationalStandardsspecifyingsuchmaterials. ENISO7491:2000 1 DentalmaterialsDeterminationofcolourstability 1 Scope ThisInternationalStandardspecifiesamethodforthedeterminationofthecolourstabilityofdentalmaterialsafter e
24、xposuretolightandwater. 2 Normativereferences Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thisInternationalStandard.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthese publicationsdonotapply.However,partiestoagreementsbasedont
25、hisInternationalStandardareencouragedto investigatethepossibilityofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.For undatedreferences,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIEC maintainregistersofcurrentlyvalidInternationalStandards. ISO3696,Wate
26、rforanalyticallaboratoryuseSpecificationandtestmethods. ISO4892-2,PlasticsMethodsofexposuretolaboratorylightsourcesPart2:Xenon-arcsources. CIEPublication15.2,Colorimetry. 3 Testmethods 3.1 Apparatus 3.1.1 Radiationsource Xenonmedium-pressurelampwithacolourtemperatureof5000Kto10000Kandwithanilluminan
27、ceatthe specimenof150000lx.Anydeviationoftheilluminancefromthemeanvalueatanygivenmomentshallnot exceed 10%overtheentireareaoccupiedbythetestspecimen,measuredinaccordancewithISO4892-2. Otherradiationsourcesofperformanceequivalenttothexenonlamparealsosuitable. Thexenonlampandtheultravioletfilter(3.1.2
28、)shouldnormallybereplacedafter1500husebecauseofthe changeinradiationintensityduetoageing.Theilluminanceshouldbemeasuredwithasuitableilluminationmeter andtheilluminanceadjustedaccordingly. 3.1.2 Ultravioletfilter,ofborosilicateglass,withtransmittanceoflessthan1%below300nmandgreaterthan 90%above370nm.
29、 3.1.3 Testchamber Thetestchambercomprisesthefollowingcomponents. ENISO7491:20002 3.1.3.1 Circulatingwaterbath Thewater,complyingwithgrade2ofISO3696,shallbemaintainedat(37 5) Candatadepthof(10 5)mm abovethespecimens,whichareheldparalleltothebottomofthechamber. 3.1.3.2 Specimenholder,ofanopaquemateri
30、al,preferablymetal,forspecimendiscsupto50mmdiameter. AsuitableholderisshowninFigure1. Dimensionsinmillimetres Key 1 Clampingplate 2 Baseplate 3 Screw 4 Spacer,ofdimensiondadjustedtothethicknessofthespecimen NOTE Theholdermaybedesignedforoneorseveralspecimens. Figure1Holderforspecimendiscsupto50mmdia
31、meter 3.2 Procedure 3.2.1 Specimenpreparation Individualdentalmaterialstandardsspecifyspecimensize,methodofpreparationandconditioningaswellasthe methodofpreparingareferencespecimen.SuchstandardsshallbeusedinconjunctionwiththisInternational Standard. 3.2.2 Radiationtest Eitherclampone-halfofthespecim
32、enintheholder,asshowninFigure1,orcoverone-halfofthespecimenwith tinoraluminiumfoil.Forspecimenteeth,coverhalfofthevestibularsurfacewithtinoraluminiumfoilparalleltothe longaxisofthetooth. Withtheultravioletfilter(3.1.2)inposition,placethetestspecimensinthewaterbathandexposethemtothe radiationofthexen
33、onlamp(3.1.1)for(24 1)h.Takecaretoavoidcastingshadowsonthespecimens. ENISO7491:2000 3 3.2.3 Colourcomparison Usethreepeoplewithnormalcolourvisiontocomparebyvisualinspectiontheexposedandunexposedhalvesof eachofthespecimensandtheunirradiatedspecimenforanycolourdifferences.Thenormalcolourvisionofthe ob
34、serversshallbeverifiedbyamedicalpractitionerorotherappropriatelytrainedperson.Correctiveuntinted lensesmaybeworn. Makethecomparisoninbrightdiffusedaylightunderanovercast“northern/southern“skyor,alternatively,undera xenonorequivalentlampcorrespondingtoD65,inaccordancewithCIEPublication15.2,withoutany
35、significant colouredreflectionandusinganilluminanceof1000lxto2000lx. Fordisc-shapedspecimens,placeadiffusewhitebackgroundofreflectanceabout90%(whitebondpaperis suitable)behindthesamples.Limitthebackgroundtothesizeofthediscandsurrounditbyadiffusegrey backgroundwithareflectanceof(30 5)%. Fortooth-shap
36、edspecimens,useadiffusegreybackgroundwithareflectanceof(30 5)%. Allowthethreeobserverstoviewthespecimensatadistanceof200mmto300mmforaperiodofnotlonger than2s. Recordtheindependentcomparisonsofthethreeobservers.Intheeventofdisagreementbetweentheobservers, themajorityviewshallbereported. ENISO7491:200
37、04 Bibliography 1 ISO4582:1998,PlasticsDeterminationofchangesincolourandvariationsinpropertiesafterexposure todaylightunderglass,naturalweatheringorlaboratorylightsources. 2 ISO4892-1:1994,PlasticsMethodsofexposuretolaboratorylightsourcesPart1:Generalguidance. ENISO7491:2000AnnexZ A (normative) Norm
38、ativereferencestointernationalpublications withtheirrelevantEuropeanpublications ThisEuropeanStandardincorporatesb ydatedorundate dreference,provisionsfromotherpublications. These normative references are cited at the appropriateplacesinthetextandthepublicationsarelisted hereafter.Fordatedreferences
39、,subsequentamendmentstoorrevisionsofanyofthesepublications applytothisEuropeanStandardonl ywhenincorporatedini tbyamendmentorrevision.Forundated referencesthelatesteditionofthepublicationre ferredtoapplies. Publication Year Title EN Year ISO 3696 1987 Waterforanalyticallaboratoryuse Specificationand
40、test methods ENISO3696 1995 ISO48922 1994 PlasticsMethodsofexposureto laboratorylightsourcesPart 2: Xenonarcsources ENISO48922 1999 ENISO7491:2000BS EN ISO 7491:2000 BSI 389 Chiswick High Road London W4 4AL | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
41、 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view
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