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Remavable artial denture

Hebah ra3d ramadneh

3essam el-3alam

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Removable Partial DenturesInthissemesterwewilltalkaboutremovablepartialdenture,whichis moredifficultthancompletedenturebecauseitssmallerandneedotherstepstobe

done. isaprosthesisthatreplacesoneormoremissingteeth.(not

allteeth)

Inpartialprosthodonticswehave2types:1-interimprosthodontics(Interim (transitional)) :( , , )***Itsalmost(notalways)madebyacrylic(looklikecompletedenture),ithasclasps .

2-diffinitiveprosthodontics(permanent):thefinalone

***ithasmetalframeworkitsusuallymadeofcobaltchromiumwhichisverystrongmaterial(notcorrodeeasily)&itsbiocompatibleforthetissueinthemouth.

wecanalsousenickelchromium itsastrongmaterial,butitsstillhasproblemwiththetissueinthemouth,5%ofpeoplehasnickelsensitivityso,wetrynottousenickelindentistry.

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NOTE:_weusechromiumtoprotectthecobaltmaterialbecausechromiumisfastertoreactwithoxygen._Inthelabwewillmakemetalframeworkdenture.Intheclinicyouwillmeetdifferentcaseswithdiferentmissingteethso,itsdifficulttodescribeeachcasetothetechnicianssowehavedifferentclassificationsystemsweredesigned,andtheseweredoneinNorthAmerica .Theclassificationsystemthatyouhavealreadybeenfamiliarwithis

with .DrKennedyproposedthisclassification90yearsago,Kennedysclassificationhassomedeficienciesand

thatswhyMr.Applegatecamealongandmadesomemodifications. Wehavedifferentclassesinkennedysclassification:

*class-I:themostmissingteeth,theanteriorteethispresentbuttheposteriorteethislost.wecandescribeitasbilateraldisextension( Bilateral edentulous).itcanbeupperorlowerbutinbothside(bothsidemissing).

*class-II:insteadofhavingmissingteethinbothside,wehavemissingteethinoneside,itsunilateraldisextension, Unilateral edentulous(onesidemissing).

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*class-III:wehavespacedmissingteeth,thatmeanmissingteethintheanteriorandposteriorpartofthemouthwecalleditboundspaced( ).itsaUnilateralareaboundedbyanterior&posteriornaturalteeth.

*class-IV:itsjustlikeclass-IIIbutitsspecial,itbilateralcrossthemidline.

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Applegatesmodifications:thefirstoneisspacemodification:

youhaveadditionalspace,ithasnothingtodowiththenumberofmissingteeth,itdealwiththenumberofmissingspace.EXs:-ifyouhavepatientwithkennedysclass-Iandhemisshiscentralincisoryou

calleditkennedysclass-Imodification-1 .ifthispatientalsolosthislateralincisorinthesamesidewealsocalleditkennedysclass-Imodification-becauseitsdealwithnumberofspacesnotthenumberofthemissingteeth.- ifyouhavepatientwithkennedysclass-IandhemisshiscanineandlateralincisorintheRtandintheLf,wecalleditkennedysclass-Imodification-1-2

***WECOUNTTHESPACESNOTTHEMISSINGTEETH***

-NOTE:Thereis modificationspacein ).OnlyClassI,II,IIhasmodificationspace.becauseI take the most posterior edentulous area and the anterior spacebecomes a modification.

In Ihave edentulousspace,thereisamistakeintheslidesitsnotbilateralitsjustunilateral(oneedentulousarea,itcanbe2butithas

differentname),nowifthisspacecrossesthemidlineitbecomes .

Sometimesthereareothermissingspaces,notthetypicalformthatKennedytalkedabout.ForexampleifIhaveatooth

Remember this:

Class I . 2 edentulous areasClass II.1 edentulous area.

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missinghere(thestarinthepicture),whatshouldIcallit??ThereisanApplegatesrulesaysthatIalwayschoosethe posterioredentulouspart,theonethatisthemostposterioristhedistalextension,whichisKennedy'sclassII,whatshouldIcalltheotherspace(hereitsthestar)??ApplegatesaidthatifIhaveanadditionaledentulousareaIdontcaretothenumberofteeth,itcouldbeoneortwo,andeachadditionalmissingspaceiscalleda

,notaccordingtothenumberofmissingteethbutaccordingtotheboundedspaces.Sothisis .TheotherproblemwithKennedy'sclassesis,hereIhave ,whatifIhaveteethmissing,herethestarsinthepicture>>>

Itakethe edentulousareaandtheanteriorspacebecomesa EventhoughitcrossesthemidlinewhichisanotherruleofApplegate(Thereis modificationspacein ).ClassI,II,IIIcanhaveamodification,itscommonsense,ifIhaveclassIVmodificationI(whichcanthappen)itshouldbeclassIIIanyway,hereismyexplanationanyedentulousareaotherthantheoneinclassIVwillbeforsureintheposteriorpartbecauseclassIVshould

crossthemidlinewhichmeansthatitsanteriortoanyedentulousareasandasApplegatesaidthatwechoosethemostposterior,soifIhaveanyadditionaledentulousareawithclassIVitwilltransformtoamodificationinsteadofaclassbyitself.

Nowwewilltalkabout3rdmolar:

manypeoplebornwithout3

rd

molarsowecantincludeitinourcalcification(if the third molar is not included in my design, its not included in theclassification ) .

SometimesthereareteethinthemouththatIdontuseinmydesign.WhatifItellyouthatthisupper3 rdmolarhasnolower3 rdmolarsousuallyinApplegate

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modificationyouwillseethatifthethirdmolarisnotincludedinmydesign,itsnotincludedintheclassificationsoifImnotusingthe3 rdmolar,thisbecomesaunilateralextensionofedentulousareawhichis

Now this is true for 3rd

and 2nd

molar, unless I give you specific information then youhave to take specific default, now again lets go to Applegates rules.

1-Classification should follow rather than precede extraction:If a patient come to you and has a periodontal disease extract the teeth

then make the classification, or imagine the patient without that tooth or teeth.

2- If 3rd molar is missing & not to be replaced, it is not considered in theclassification.

3-If the 3rd molar is present and to be used as an abutment, it is considered in theclassification.

4-If the second molar is missing and not to be replaced, it is not considered in theclassification.

5-The most posterior edentulous area determines the classification.6-Edentulous areas other than those determining classification are called

modification spaces.

7-The extent of the modification is not considered, only the number.8-There is no modification space in Class IV.

If I delete this molar it becomes class II

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***Nowletustalkaboutveryimportantissue,whichisaboutforcesaffectthedenture,thesupportedtissue,. -Naturalteethconnectedwiththebonebyperiodontalligament(2-4mm),so,itcanmovearound0.5mminalldirection.-Inthecompletedenture,itsfixedonasofttissueabovethebonesotheboneresolvedbutthestoryisthesameinallpartofthemouthso,thepatientcompensatewiththesecondition.-inthepartialdenturetheproblemis:itssupportbysofttissueandteeth

so,thetoothwhichlocateattheendoftheboundedspacewillaffectedbymoreforce,moreloadbecausethemotionandrotationwillbearounditandwithtimeitwillbelost,BUTourjobistomaintainthehealthytissuewhichisexistthere.So,ifyouhaveteethinonepartofthemouthandnoteethintheotherpartthenyouhaveabigproblem

so,nowwehaveothertypeofcalcificationwhichdependontheloaddistreputionandsupportform:***inthecompletedenturewehave or

(alldenturesupportedbytissue).***inthemetalframeworkpartialdenturewehave3story(accordingtokenndysclasses):1-class-III&class-IV(shortspan),wehaveteethinbothsideofboundedspacesowehave . weremovepartofenamelbutnotreachthedentinethenweputthepartialdentureaboveit.2-class-I&class-II,wehavetoothinthefrontandtissueinthebackso;wehave .Andthisistheproblembecausewhenthepatientmasticatehewillcompressthetissueandputmoreloadonthetooth,,,so,nowadaysmostofourstudyistoreducetheseforceandloadtomaintaintheremainingstructureinthemouth.3-Acrylicandinterimpartialdentureandaretissue WHY?Becausetheacrylicmaterialisweakerthanmetalso,itwillruptureif

weputitabovehardpart(tooth)andbymetalwecanmakethinextensionbutbyacrylicwecantso,itslikethecompletedenture(NOtoothsupported).DONEBY:hebahramadneh! ! !!