impression-口腔专业课课件-修复

impressionandmodeltechniqueZhangXiaonan

pearl-zhang@163.comtheAffiliatedHospitalofStomatologyChongqingMedicalUniversityChapter1impressiontechniqueImpression:anegativelikenessorcopyinreverseofthesurfaceofanobject.Dentalimpression:Adentalimpressionisacopyofthemouthmadeusinganelasticmaterial.Itisanegativeofthemouthintowhichplasterordentalstoneisplacedinordertomakeanaccuratecopyofthemouth.

Themoreaccurateyourimpression,thebetteryourdentalapplianceswillfit.

Impression

CastormodelBasicconcept5Positivecast6beeswaxplasterwaxalginate(irreversiblehydrocolloids)agar(reversiblehydrocolloids)silicone,polyether,molderingwaxwithouttrayprimaryimpressionmethodsecondaryimpressionmethodcustomimpressiontraysyringe,functionalimpressionDevelopmentPart1

MixingtheAlginateandTakingNegativeImpression1UsingthesuppliedmeasuringcupMixwaterwithAlginateaccordingtothedirection.Colderwaterretardssettingandwarmerwaterspeedsupsetting.

2Therecommendedmixingtimeis1minutetoachieveacreamymix.3.4FillTray.Movequicklyyoudon’thavemuchtime.Rinsemouthwithwarmwater.Insertfilledtray;pressgentlyintoposition:pulllipoversideoftrayandholdimmovablefor1minuteafterstickinessvanishes.5UsetheleftoverAlginateinyourmixingcuptotellwhentheAlginateinyourmouthiscompletelysolidified.TheAlginateisreadywhenitisfirmtothetouchanditdoesn'tleavearesidueonyourfinger.6Usingthetabasahandle,gentlyjigglethetraysidetosidetoreleasethevacuum.Removethetrayandrinseimpressionthoroughlyunderrunningwatertoremovesalivaanddebris.Pourimpressionmaterialimmediatelytoachievethemostaccurateresults.7Yourfinishedimpressionshouldsomewhatresemblethis.Thegreaterdetailyourmold,thebetteryourdentalappliancewillfit.8“Maketheimpression”“Taketheimpression”Methodofclassification1.Basedonthetimesofmakingimpression2.Basedonpatient’mouthopenorclosed3.Basedonpressureonthemucousornot4.layeredimpression5.zoningimpressionmethod1.Basedonthetimesofmakingimpression（1)primaryimpressionmethod(2)secondaryimpressionmethod

preliminaryimpression

finalimpression（1）open-mouthimpression:musclefunctionaltrimmingisneeded.（2）closed-mouthimpression:convertpreviousortransitionaldentureintocustomtray.Fulldenturerelining.2.Basedonpatient’mouthopenorclosed

（1）anatomicimpression(non-pressure)(2)functionalimpression(selectivepressure)

3.Basedonpressureonmucousornot4、layeredimpressionTrayselectionImpressionforcompletedenturesPreliminaryimpressionandmodelDrawtheoutlineforcustomtrayImpressionforcompletedenturesCustomtrayImpressionforcompletedenturesTrimthetrayTryinImpressionforcompletedenturesBordermolding(thepolyethermaterialisplacedacrosstheposteriorpalatalsealandcontinuedaroundtheentireborderofthetrayImpressionforcompletedenturesImpressionforcompletedenturesAfterbordermolding(theborderofthetrayconformsaccuratelytothecontourofthebuccalandlabialvestibules)MakingfinalimpressionImpressionforcompletedenturesFinalimpressionandcast

ImpressionPrincipalimpressiontechnique:1.pressureonmucosa2.openorclosedmouth3.functionaltrimming4.trayselection

Differentprosthesishasdifferentrequirementforimpression.Borderextensioniscriticalforretentionofthedenture.Functionaltrimmingisthekeytotherightextension.Themostimportantfactorsinmakingsatisfactoryimpressions1.Aproperlyformedandaccuratelyfittingimpressiontray.2.Properpositioningofthetraywithinthemouth.

TrayselectionandclassificationclassificationOnthebasisofthematerialused：1.metaltray:（1）aluminum：mostwidelyused.（2）stainlesssteel：2.plastictray：one-off3.metal-plastictray：onthebasisofstructureandfunction：Fullarchtray2.Partialarchtray3.Edentuloustray1.fundermentalrequirement:Consistencywiththemorphologyofthearch,3-4mmlargerthantheoraltissue.Thebordercannotinterferewiththemovementofthefrenulum,lips,tongueandothersofttissue.trayselection2.methodofmodifyingastocktrayEvenacorrectlyselectedstocktraycannotfitthedenture-bearingareaperfectly.1）bytechniciantongs2)usingwax3.customtray（1）advantage（2）fabricateacustomtray：Spaceforthefinalimpressionmaterial“3c”principalofacustomtrayControlCarryConfirm

Classification

1.Elastic

1.1HydrocolloidReversiblehydrocolloid(Agar)Irreversiblehydrocolloid(Alginate)

1.2ElastomericPolysulfideSiliconePolyether2.Non-elastic

Zincoxideeugenol

(ZOE)ImpressionwaxImpressioncompoundImpressionplasterbasedonapplicationormechanicalproperties43

“Noimpressionmaterialfulfillsalltherequirements”

à

theselectionofthematerialbestsuitedforaparticularclinicalsituationandtechniquerestswiththedentist.44Impressionmaterial1.Impressioncompound2.Alginateimpressionmaterial3、SiliconerubberimpressionmaterialImpressionmaterialselectionandusage1.canpreparethedentalimpressionaccurately,easytouse,inexpensive.2.manipulateaccordingtothemanufacturer’sdirections.Impressionprocedure1.patientposition2.selectandmodifythetray3.maketheimpression4.precaution：（1)musclefunctionaltrimming:（2)removethetray5.examinetheimpressionMaxillaryimpressionprocedureImpressionsterilizationSterilizationofimpression1.methods1）waterrinse；2）chemicalsterilization：immersion；spray2.sterilizationmayinfluencetheaccuracyoftheimpression3.selectappropriatedisinfectant

Howtomakeanidealimpression?Chapter2modeltechniquemodel：mastermodelorcast：diagnosticcast：registercastorrecordcast：Requirement1.accuratereproductionofallthedetailsoftheimpression2.sufficientstrengthandhardnesstowithstandworkdoneuponthem.3.asmoothandhardsurface,easytoseparateofimpressionModelmaterialselectionandapplication1.super-hardstone2.hardstone3.plastermodelcasting1.method（1）generalcasting（2）boxingcasting（3）sectionalcasting:reducethecost.BoxingAwaxformisdevelopedaroundtheborderofthefinalimpressiontopreservetheshapeoftheperipheryandtosimplifymakingcastssectionalcastingThemainproblemincastingmodelsistheexclusionofairfromthemixsinceitspresenceweakensthemodels.Threemethodsusedtoeliminateasmuchairaspossible:MechanicalspatulationVibrationVaccuum2.precautionwhilecasting1）strictlyfollowtheproduct’sdirection.2）donotmixthestonetooquickly.

3）pourthestonefromthehighestpointoftheimpression4）separatetheimpressionwhenthematerialreachesitsfinalset.5）protecttheunattachedtooth.Part2MixingimpressionmaterialPutUltra-cal30intocupandsprinkleintowater,untiltheUltracal-30settlesontopandlookslikeadryriverbed.

9Mixuntilyougetanicecreamyconsistency,workoutalllumps.

10GentlyspoonsomeofthemixedUltra-cal30intothefrontofthemold,gettingitintotheimpressionofthefrontteeth.Butdon'tfillalltheway-juststartwiththefront.11HoldingDentalTraybytab,gentlytapmoldonthecornerofthetabletoremo