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ORIGINALARTICLEANINVITROANALYSISOFELEMENTALRELEASEANDCYTOTOXICITYOFRECASTNICKELCHROMIUMDENTALCASTINGALLOYSNAGAMRAJAREDDYANANDAPANDIANPONSEKARABRAHAMKRISHNANMURUGESANVASANTHAKUMARMATSARECEIVED30DECEMBER2010/ACCEPTED22MAY2011/PUBLISHEDONLINE3JUNE2011C211INDIANPROSTHODONTICSOCIETY2011ABSTRACTRECASTINGOFTHECASTINGALLOYSAFFECTSTHECOMPOSITIONANDELEMENTALRELEASEWHICHMAYHAVECYTOTOXICEFFECTDIFFERENTFROMTHEPUREALLOYINTHESURROUNDINGTISSUESANINVITROSTUDYWASCONDUCTEDTOINVESTIGATETHEELEMENTALRELEASEANDTHEIRCYTOTOXICEFFECTSFROMCOMMERCIALLYAVAILABLENICRDENTALCASTINGALLOYS,COMMONLYUSEDFORFABRICATINGFIXEDPARTIALDENTURESTHREENICRALLOYSWIRON99A,CERAMETB,ANDHINICKELCBCWERETESTEDALLOYSPECIMENSDISKS395MMWERECASTEDANDGROUPEDASFOLLOWSGROUPIA1/B1/C1100PUREALLOYGROUPIIA2/B2/C250NEWWITH50RECASTANDGROUPIIIA3/B3/C3100RECASTDISKSOFEACHALLOYTYPEFROMEACHGROUPWERETRANSFERREDTODULBECCOSMODIFIEDEAGLEMEDIUMANDLEFTFOR3DAYSAT37C176CINANATMOSPHEREOF5CO2NI,CR,CO,CUANDMOELEMENTALRELEASEFROMMETALALLOYSINTOCULTUREMEDIUMWASINVESTIGATEDUSINGINDUCTIVELYCOUPLEDPLASMAMASSSPECTROMETRYCYTOTOXICITYWASTESTEDUSINGMOUSEFIBROBLASTCELLSANDMTTASSAYCONTROLSCONSISTEDOF6WELLSCONTAININGCELLSWITHNOALLOYSPECIMENSDATAWEREANALYZEDBYTWOWAYANALYSISOFVARIANCEFOLLOWEDBYTTESTTHETOTALAMOUNTOFELEMENTSRELEASEDINPARTSPERBILLIONFORVARIOUSCASTINGGROUPSWEREGROUPI,A16572,B16732,C18407GROUPII,A222046,B226450,C229189GROUPIII,A384554,B388359,C392264MOREAMOUNTSOFELEMENTSWERERELEASEDINHINICKELCBTHANCERAMETANDWIRON99INALLTHETHREETESTGROUPSPERCENTAGEOFVIABLECELLSFROMMTTANALYSISWEREGROUPI,A162342,B161322C160593,GROUPII,A258699,B256494,C252688,GROUPIII,A353101,B352195,C347586THEVIABLECELLSPRESENTINTHECULTUREMEDIAWEREMOREINWIRON99THANCERAMETANDHINICKELCBELEMENTALRELEASEINCREASEDWITHAMOUNTOFRECASTALLOYAMONGSTTHETHREEALLOYSTESTEDHINICKELCBHADSIGNIFICANTLYHIGHERELEMENTSRELEASEDCOMPAREDTOCERAMETANDWIRON99IN100PUREALLOYS,50RECASTAND100RECASTALLOYSWIRON99SHOWEDLEASTELEMENTRELEASEIN100PUREALLOY,50RECASTAND100RECASTSPECIMENS100PUREALLOYSOFALLTHREEALLOYSARELESSCYTOTOXIC,BUTTHEIRCYTOTOXICITYISMOREON50AND100RECASTEDALLOYSOUTOFALLTHREEVARIATIONSOFCASTINGWIRON99WASLEASTCYTOTOXIC,FOLLOWEDBYCERAMETANDHINICKELCBRECASTINGOFALLOYSSIGNIFICANTLYINCREASEDTHEELEMENTSRELEASEDANDTHEIRCYTOTOXICITYKEYWORDSRECASTINGC1CYTOTOXICITYC1ELEMENTALRELEASEC1DENTALCASTINGALLOYSC1BASEMETALINTRODUCTIONADVANCESINSCIENCEANDTECHNOLOGYINTHEFIELDOFDENTALMATERIALSCIENCEHAVELEADTOTHEINVENTIONOFBASEMETALALLOYSFORAPPLICATIONINDENTISTRY1INTRODUCTIONOFCHROMEALLOYSHASPROVIDEDANALTERNATIVETOGOLD,WITHTHESERESULTEDINNICRANDCOCRBASEDALLOYSWHICHARECLINICALIMPLICATIONSCASTRESTORATIONSPLACEDINCLOSECONTACTWITHORALTISSUESFORVARIOUSPERIODSOFTIMEMAYELICITLOCALADVERSETISSUEREACTIONSSUCHASGINGIVITISANDPERIODONTITISADJACENTTOTHEMDEGREEOFCYTOTOXICITYANDBIOCOMPATIBILITYOFDENTALCASTINGALLOYSHASBEENRELATEDTOALLOYCOMPOSITIONANDELEMENTSRELEASEDFROMALLOYSINTOSURROUNDINGMEDIUMRECASTINGOFNICRALLOYSINCREASESTHEAMOUNTOFELEMENTSRELEASEDANDHENCETHECYTOTOXICPOTENTIALNRREDDYCKSTEJAINSTITUTEOFDENTALSCIENCES,TIRUPATHI,ANDHRAPRADESH,INDIAAPABRAHAMTABLE1ALLOYSHAVEBEENCODEDFORSIMPLICITYANDREFERENCEPURPOSESPREPARATIONOFALLOYSPECIMENSANALUMINIUMMETALDIEWITHACIRCULARSPACEOF5MMRADIUSAND3MMDEPTHWASMILLEDINTHECENTREPORTIONOF1CMTHICKALUMINIUMBLOCKUSINGCOMPUTERIZEDMILLINGMACHINEFIG2WAXPATTERNS10MMINDIAMETER93MMTHICKNESSWEREPREPAREDWITHGREENINLAYCASTINGWAXFIG3BEGOGERMANYUSINGTHEMETALDIEATOTALOF108WAXPATTERNSWEREMADEFORTHREEALLOYSFORGROUPI100PUREALLOYA1/B1/C1,GROUPII50PURE50RECASTALLOYA2/B2/C2,ANDGROUPIII100RECASTEDALLOYA3/B3/C3CASTINGOFTHEPATTERNTHEWAXPATTERNSOFTHETHREEGROUPSWERESEGREGATEDASGIVENINTABLE2THESPRUEDWAXPATTERNSWEREINVESTEDINPHOSPHATEBONDEDINVESTMENTINMETALCASTINGRINGWITHDRYCELLULOSEPAPERRINGLINERFOLLOWINGTHISTHEYWERECASTEDBYLOSTWAXTECHNIQUEINANINDUCTIONCASTINGMACHINEFIG4BEGOGERMANYWITHTHERESPECTIVEALLOYSMETALSUSEDFORRECASTINGWASOBTAINEDFROMCLEANEDLEFTOVERSPRUESANDBUTTONSOFTHEALLOYSTHATHADBEENPREVIOUSLYCASTINGROUPIAFTERBENCHCOOLINGTHECASTINGRINGWASDIVESTEDANDSANDBLASTEDUSING250LMALUMINIUMOXIDETOREMOVETHEREMNANTINVESTMENTMATERIALSPRUESWERECUTOFFANDSPECIMENSWEREFINISHEDANDPOLISHEDUSINGCARBORUNDUMDISCS,METALTRIMMERS,RUBBERWHEELS,SANDPAPERSANDPOLISHINGCAKEUSINGHANDMOTORINSTRUMENTSTHEPOLISHEDDISKSWERESOAKEDINADETERGENTSOLUTIONFOR5MINANDTHENSCRUBBEDUSINGASOFTBRISTLEBRUSHANDRINSEDUNDERTAPWATERFOR5MINSPECIMENSWERETHENREPLACEDINSTERILEDISTILLEDWATERANDCLEANEDBYSONIFICATIONANDAUTOCLAVEDATATEMPERATUREOF150C176CFOR60MINELEMENTALRELEASESIXDISKSOFEACHALLOYTYPEFROMEACHGROUPWERETRANSFERREDTO6MLOFDULBECCOSMODIFIEDEAGLEMEDIUMDMEMANDINCUBATEDFOR3DAYSAT37C176CINANATMOSPHEREOF5CO2DMEMISPREPAREDBYSUPPLEMENTINGWITH5NEWBORNCALFSERUM,100U/MLOFPENICILLIN,STREPTOMYCINAND025LGM/LAMPHOTERICINBFIG5THEMEDIAWASANALYZEDFORPRESENCEOFNI,CR,MO,CO,ANDCUUSINGANINDUCTIVELYCOUPLEDPLASMAMASSSPECTROMETRYICPMSMEDIUMWASDILUTEDWITHDEIONIZEDWATERANDKEPTINICPMSANDTHEREADINGSWERERECORDEDTRIPLICATEABSORBANCEWASUSEDTODETERMINETHEMEANCONCENTRATIONOFDIFFERENTELEMENTSINPARTSPERBILLIONPPBRELEASEDFROMALLOYSFIG1NICRALLOYSFORMETAL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