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外文翻译--关于重铸合金镍铬牙科铸造合金中元素的释放和细胞毒性的体外分析 英文版【优秀】.pdf外文翻译--关于重铸合金镍铬牙科铸造合金中元素的释放和细胞毒性的体外分析 英文版【优秀】.pdf -- 10 元

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ORIGINALARTICLEAnInvitroAnalysisofElementalReleaseandCytotoxicityofRecastNickel–ChromiumDentalCastingAlloysNagamRajaReddyAnandapandianPonsekarAbrahamKrishnanMurugesanVasanthakumarMatsaReceived30December2010/Accepted22May2011/Publishedonline3June2011C211IndianProsthodonticSociety2011AbstractRecastingofthecastingalloysaffectsthecompositionandelementalreleasewhichmayhavecytotoxiceffectdifferentfromthepurealloyinthesurroundingtissues.AnInvitrostudywasconductedtoinvestigatetheelementalreleaseandtheircytotoxiceffectsfromcommerciallyavailableNi–Crdentalcastingalloys,commonlyusedforfabricatingfixedpartialdentures.ThreeNi–CralloysWiron99A,CerametB,andHiNickelCBCweretested.Alloyspecimensdisks395mmwerecastedandgroupedasfollowsGroupIA1/B1/C1100purealloyGroupIIA2/B2/C250newwith50recastandGroupIIIA3/B3/C3100recast.DisksofeachalloytypefromeachgroupweretransferredtoDulbeccosmodifiedeaglemediumandleftfor3daysat37C176Cinanatmosphereof5CO2.Ni,Cr,Co,CuandMoelementalreleasefrommetalalloysintoculturemediumwasinvestigatedusingInductivelyCoupledPlasmaMassSpectrometry.CytotoxicitywastestedusingmousefibroblastcellsandMTTAssay.Controlsconsistedof6wellscontainingcellswithnoalloyspecimens.Datawereanalyzedbytwowayanalysisofvariancefollowedbyttest.ThetotalamountofelementsreleasedinpartsperbillionforvariouscastinggroupswereGroupI,A16.572,B16.732,C18.407GroupII,A222.046,B226.450,C229.189GroupIII,A384.554,B388.359,C392.264.MoreamountsofelementswerereleasedinHiNickelCBthanCerametandWiron99inallthethreetestgroups.PercentageofviablecellsfromMTTanalysiswereGroupI,A162.342,B161.322C160.593,GroupII,A258.699,B256.494,C252.688,GroupIII,A353.101,B352.195,C347.586.TheviablecellspresentintheculturemediaweremoreinWiron99thanCerametandHiNickelCB.Elementalreleaseincreasedwithamountofrecastalloy.AmongstthethreealloystestedHiNickelCBhadsignificantlyhigherelementsreleasedcomparedtoCerametandWiron99in100purealloys,50recastand100recastalloys.Wiron99showedleastelementreleasein100purealloy,50recastand100recastspecimens.100purealloysofallthreealloysarelesscytotoxic,buttheircytotoxicityismoreon50and100recastedalloys.OutofallthreevariationsofcastingWiron99wasleastcytotoxic,followedbyCerametandHiNickelCB.Recastingofalloyssignificantlyincreasedtheelementsreleasedandtheircytotoxicity.KeywordsRecastingC1CytotoxicityC1ElementalreleaseC1DentalcastingalloysC1BasemetalIntroductionAdvancesinscienceandtechnologyinthefieldofdentalmaterialsciencehaveleadtotheinventionofbasemetalalloysforapplicationindentistry1.Introductionofchromealloyshasprovidedanalternativetogold,withtheseresultedinNi–CrandCo–CrbasedalloyswhichareClinicalImplicationsCastrestorationsplacedinclosecontactwithoraltissuesforvariousperiodsoftimemayelicitlocaladversetissuereactionssuchasgingivitisandperiodontitisadjacenttothem.Degreeofcytotoxicityandbiocompatibilityofdentalcastingalloyshasbeenrelatedtoalloycompositionandelementsreleasedfromalloysintosurroundingmedium.RecastingofNi–Cralloysincreasestheamountofelementsreleasedandhencethecytotoxicpotential.N.R.ReddyCKSTejaInstituteofDentalSciences,Tirupathi,AndhraPradesh,IndiaA.P.AbrahamC1K.MurugesanC1V.MatsaDepartmentofProsthodonticsandCrownBridge,SRMDentalCollege,SRMUniversity,Ramapuram,Chennai,Indiaemaildrponabegmail.com123JIndianProsthodontSocAprJune2011112106–112DOI10.1007/s1319101100758renrendoc.comconsideredaseconomicallylessexpensiveandalsohavetherequiredqualitiesandbiocompatibilityforusageindentalrestorativework2,3.Basemetalalloysarepronetovarioustypesofcorrosiondependingonitscompositionandoralenvironment1.Thereleaseofmetallicelementsfromdentalalloysisapotentialhealthproblemtodentalpatient4.Metalsareknowntocausetoxicinflammatoryallergicormutagenicreactions.Importantconsequenceofelementalreleaseiscytotoxicityofadjacenttissuesincellcultures5,6.Castrestorationsbeingplacedinclosecontactwithoraltissuesforvariousperiodsoftimemayelicitlocaladversetissuereactionssuchasgingivitisandperiodontitisadjacenttothem.Degreeofcytotoxicityandbiocompatibilityofdentalcastingalloyshasbeenrelatedtoalloycompositionandelementsreleasedfromalloysintosurroundingmedium7.Recastingofusedalloysintheformofspruesordefectivecastinghasbeenpracticedtopreventwastageofmaterialaftercasting3.Identificationoftheelementsandtheirconcentrationsresponsibleforcytotoxiceffectsisimportantbecauseitwillhelpinimprovinganddesigningneweralloystoavoidthereleaseofelementswhichareharmfultooralcavity.Hypothesisofthestudywasthatrecastingofbasemetalalloyswouldchangethechemicalpropertiesofthealloysandthusaffecttheirelementalreleaseandsubsequentlyelicitcytotoxiceffects.TheaimofthisinvitrostudywastoinvestigatetheeffectsofrecastingofNi–Crbasemetalalloysandtheirpotentialcytotoxiceffectsandelementalreleaseintoculturemedia.ObjectivesofstudyweretoassesstheelementalreleaseandcytotoxicityofNi–CralloysandcorrelateelementalreleasewithcytotoxicityofpurealloyGroupI,50pureand50recastedGroupIIand100recastedGroupIIIalloy.MaterialsandMethodsTheinvitrostudywasundertakenwithNi–CralloyformetalceramicfromthreedifferentmanufacturersFig.1Table1.Alloyshavebeencodedforsimplicityandreferencepurposes.PreparationofAlloySpecimensAnaluminiummetaldiewithacircularspaceof5mmradiusand3mmdepthwasmilledinthecentreportionof1cmthickaluminiumblockusingcomputerizedmillingmachineFig.2.Waxpatterns10mmindiameter93mmthicknesswerepreparedwithgreeninlaycastingwaxFig.3BegoGermanyusingthemetaldie.Atotalof108waxpatternsweremadeforthreealloysforGroupI100purealloyA1/B1/C1,GroupII50pure50recastalloyA2/B2/C2,andGroupIII100recastedalloyA3/B3/C3.CastingofthePatternThewaxpatternsofthethreegroupsweresegregatedasgiveninTable2.Thespruedwaxpatternswereinvestedinphosphatebondedinvestmentinmetalcastingringwithdrycellulosepaperringliner.FollowingthistheywerecastedbylostwaxtechniqueinaninductioncastingmachineFig.4BegoGermanywiththerespectivealloys.MetalsusedforrecastingwasobtainedfromcleanedleftoverspruesandbuttonsofthealloysthathadbeenpreviouslycastingroupI.Afterbenchcoolingthecastingringwasdivestedandsandblastedusing250lmaluminiumoxidetoremovetheremnantinvestmentmaterial.Sprueswerecutoffandspecimenswerefinishedandpolishedusingcarborundumdiscs,metaltrimmers,rubberwheels,sandpapersandpolishingcakeusinghandmotorinstruments.Thepolisheddisksweresoakedinadetergentsolutionfor5minandthenscrubbedusingasoftbristlebrushandrinsedundertapwaterfor5min.Specimenswerethenreplacedinsteriledistilledwaterandcleanedbysonificationandautoclavedatatemperatureof150C176Cfor60min.ElementalReleaseSixdisksofeachalloytypefromeachgroupweretransferredto6mlofDulbeccosmodifiedeaglemediumDMEMandincubatedfor3daysat37C176Cinanatmosphereof5CO2.DMEMispreparedbysupplementingwith5newborncalfserum,100U/mlofPenicillin,Streptomycinand0.25lgm/lAmphotericinBFig.5.ThemediawasanalyzedforpresenceofNi,Cr,Mo,Co,andCuusinganInductivelyCoupledPlasmaMassSpectrometryICPMS.MediumwasdilutedwithdeionizedwaterandkeptinICPMSandthereadingswererecorded.Triplicateabsorbancewasusedtodeterminethemeanconcentrationofdifferentelementsinpartsperbillionppbreleasedfromalloys.Fig.1Ni–CralloysformetalceramicJIndianProsthodontSocAprJune2011112106–112107123renrendoc.comCellCultureandCytotoxicityTestForCytotoxicitytest,theremaining6disksfromvariouscastingalloysinthreegroupswereplacedincenterofa24welltissuecultureplateand0.5mlofmousefibroblastcellsuspensionwasaddedtocellwellFig.6andwereleftfor2h.Followingthis0.5mlofDMEMwasaddedandcellswereincubatedfor3daysat37C176Cinanatmosphereof5CO2.Thecontrolsconsistedof6wellscontainingcellswithnoalloyspecimens.AftertheincubationperiodtheplateswereremovedfromincubatorandcytotoxicityofTable1DescriptionofNi–CrdentalcastalloysCompositionasprovidedbymanufacturerSerialNo.TradenameManufacturerCompositionwtCode1Wiron99BegoGermanyNickel65AChromium22.5Molybdenum9.5Niobium1Silica1Iron0.5Cesium0.52CerametLabolineEuropeNickel62BChromium26Molybdenum10Silica1.5Others0.53HiNickelCBHikariJapanNickel60CChromium10Copper15Manganese7.9Others7.1Fig.2MilleddieFig.3WaxpatternsFig.4CastspecimensTable2DistributionofspecimensGroupTypeNo.ofalloyspecimenAWiron99BCerametCHiNickelCBI100New12A112B112C1II50New–50recast12A212B212C2III100Recast12A312B312C3108JIndianProsthodontSocAprJune2011112106–112123renrendoc.commaterialswasassessedbymeasuringSuccinicDehydrogenaseactivitySDHofthecellsbyusingMTTassay.MTTreagentisaddedtothecultureplatewithalloyspecimensanditistransferredto96wellplatesforreadingsinEnzymeLinkedImmunosorbentAssayELISAreader,theprotocolfollowedfortheMTTAssayissummarizedinTable3.ThereadingswerecalculatedbytheformulaCellViability¼MeanabsorbanceofsampleC2100MeanabsorbanceofcontrolStatisticalAnalysisTheresultsobtainedfromtheMTTanalysisandICPMSanalysiswassubjectedtostatisticalanalysis.OnewayANOVAwasusedtocalculatethePvalue.MultiplerangetestsbyTukey–HSDprocedurewereemployedtoidentifythesignificantgroupsat5level.ResultsElementalReleaseElementalreleasewasseeninallthreecastingalloygroups.ElementsreleasedwereNi,Cr,Co,CuandMo.Tables4,and5summarizetheelementalreleasebydifferentcastedalloysinthreecastingprocedures.HiNickelCBhadthehighestamountofelementalreleaseamongthethreecastingalloysfollowedbyCerametandWiron99.ElementalreleasesignificantlyincreasedwiththepercentageofrecastmaterialusedinforallelementsanalyzedinthestudywithP\0.05Graph1.CytotoxicityResultsThepercentageofviablecellsinthreegroupsistabulatedinTable6.MeanpercentagesofcellactivityofthreebasemetalalloysforthreecastingconditionswereanalyzedandcytotoxicitywasobservedtobemoreinHiNickelCB,followedbyCerametandWiron99.Resultsshowedthat100recastalloyshadmorecytotoxicitythan50pureand50recastedand50pureand50recastedalloyhadmorecytotoxicitythanpurealloyGraph2.DiscussionMetalshavebeenanintegralpartofdentalrestorativeprocedures.Dentalcastingalloyswhichrestoretheformandfunctionofmissingtoothstructureshouldbebiologicallyinert.Releaseofmetallicelementsfromdentalcastingalloysisapotentialhealthproblem2,8.Metalionsleachedfromcastingalloysareknowntocausetoxicinflammatory,allergicormutagenicreactions9,10.Thesereleasedelementshavebeendetectedbyinvitroandinvivostudies.Animportantconsequenceofelementreleaseisitscytotoxiceffectonadjacenttissueandtheamountoftissuereactiondependsuponelementreleased.5–7,11,12.Fig.5DulbeccosmodifiedeaglemediumDMEMFig.6Tissuecultureplatewith0.5mlofmousefibroblastcellsuspensionTable3ProtocolforperformingMTTassayStepAction1Platecellsat1,000–100,000perwell2Incubatefor6–24h3Add10llMTTreagent4Incubatefor2–4huntilpurpleprecipitateisvisible.5Add100lldetergentreagent6Leaveatroomtemperatureinthedarkfor2h7Recordabsorbanceat570nmJIndianProsthodontSocAprJune2011112106–112109123renrendoc.com
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