Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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Mandibularmajorconnector Specialstructuralrequirement

Ingeneral,mandibularmajorconnectorsarelongandnarrow,thereforespecialconsiderationmustbegiventothedesignofsuchconnectors.

Reliefisprovidedforsofttissueunderallportionsofmandibularmajorconnectorandanylocationwheretheframeworkcrossthegingivalmargin.Theinferiorborderofalingualmandibularmajorconnectormustbelocated,sothatitdoesnotimpingeonthetissueinthefloorofthemouthbecauseitchangeselevationsduringthenormalactivitiesofmastication,swallowing,speaking,lickingthelips---etc.Themetalshouldbehighlypolishedonthetissuesidetominimizeplaqueaccumulation.

Itisimportanttonotethatbeadlinesarenotusedinconjunctionwithmandibularmajorconnector.Contactwithfriablemucosaofthemandibulararchmaycauseirritation,ulcerationandpatientdiscomfort.

Sixtypesofmandibularmajorconnectorsare:

1-Lingualbar.

2-Linguoplate(lingualplate).

3-Sublingualbar.

4-Lingualbarwithcingulumbar(doublebar).

5-Cingulumbar.

6-Labialbarandbuccalbar.

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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Lingualbar&lingualplatemajorconnectorsareusedinthemajorityofremovablepartialdentureapplications.Doublelingualbarandlabialbarmajorconnectorsareusedforspecialapplicationsinwhichlingualbarsandlingualplatesarecontraindicated.

lbarlingua-1 Isthemostfrequentlyusedmandibularmajorconnector,becauseofitssimplicityindesignandconstruction.

Indication: Itisthefirstchoicemajorconnector,shouldbeusedwheneverthefunctionaldepthfromfreegingivalmargintothelingualvestibuleequalorexceed8mm.

Design: 1.thebarshouldbehalfpear-shapedincrosssection.superiorinferiordimensionis5mm,and2mminthickness. 2.thesuperiorborderofthebarshouldbelocatedatleast3mmfromthegingivalmarginsofalladjacentteeth. 3.theinferiorborderplacedatthefunctionaldepthofthelingualvestibule. 4.relifofthetissuesurfaceofthebarisnecessary.

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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:dvantagesA 1.thesimplestmandibularmajorconnectorwithhighestpatientacceptance. 2.itdoesnotcovertheteethorthegingivaltissues disadvantages: Ifitisnotproperlydesigneditmaynotberigid.

lingualplate-2 Half–pearshapedlingualbarwithathin,solidpieceofmetalextendingfromitssuperiorborder.thisthinprojectionofmetaliscarriedontothelingualsurfacesoftheteethandpresentsascallopedappearance.

Theinferiorborderofalingualplateshouldbepositionedaslowinthefloorofthemouthaspossible.butshouldnotinterferewiththefunctionalmovementsofthetongueandsofttissues.

Thesuperiorborderofalingualplatemustbecontouredtointimatelycontactthelingualsurfacesoftheteethabovethecingula.

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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s:Indication 1-usedwhenthereisinsufficientverticalspaceforalingualbar(distancefromfreegingivalmargintofloorofthemouthlessthan8mm)

2-whenthereisgingivalrecession,highmuscleattachmentsorhighfrenumattachmentsonthelingualaspectofthemandibulararch.

3-whentheremainingteethhavelostmuchoftheirperiodontalsupportandrequiresplinting.Lingualplateusedtostabilizetheremainingteethandtodistributeappliedforcesovertheremainingteethandsofttissue.

4-lingualtoriispresent.

esadvantag 1.Themostrigidmandibularmajorconnector.

2.Itgivesindirectretentiontothepartialdenture.

3.Deflectfoodfromimpactingonlingualtissues.

4.Provideresistanceagainsthorizontalorlateralforces.

5.Permitsthereplacementoflostteethwithoutremakingthepartialdenture. 6.Helpinsplintingandpreventupper-eruptionoftheanteriorteeth

Disadvantages: Inpatientwithpoororalhygiene,lingualplateextensivecoveragemaycontributetodecalcificationofenamelsurfacesandirritationofthesofttissueinpatientswithpoororalhygiene.

withcingulumbarlingualbar-Double-3 :Indications

1.Whenindirectretentionisrequired.

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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2.Whenperiodontallyaffectedteeththatrequiresplintingarepresent. :Design

1.Itismadeoftwobars;cingulambar(Kennedybar)andtheconventionallingualbar.Arigidminorconnectorattheembrasurebetweenthecanineandfirstpremolarsjoinsthetwobars.Restsareplacedateachendoftheupperbarattachedtotheminorconnector. 2.Thelowerbarhasthesamedesignasasinglelingualbar. 3.Theupperbarisscalloped,andhalf-ovalincrosssection(2-3mmhigh,and1mmthickatitsgreatestdiameter.

Advantages 1-provideindirectretention.

2-contributetohorizontalstabilization

3-nogingivalmargincoverage.

-:DISADVANTAGES

Tongueannoyance1

ntimatecontactwiththeteeth.foodimpactioniftheupperbarisnoti-2

Cingulumbar-4

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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Indications 1-heightofactivatedlingualfrenumandfloorofthemouthatthesamelevelasmarginalgingiva

2-inoperabletoriorexostosisatthesamelevelasthemarginalgingiva

3-severlyundercutlingualalveolus

4-considerablegingivalrecession.

SCONTRAINDICATION

1-anteriorteethseverelytiltedtothelingual

2-diastemaandopencervicalembrasureswherethemetalwillshow.

Advantages:

1-canbeusedwherelingualbarandlingualplatecannot.

2-doesnottransversethemarginalgingivaoroverlythelingualalveolus.

3-easytoaddprostheticteethtoframework.

-Disadvantages:

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

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Mustbebulkytohavesufficientrigidityandthusmaybeobjectionabletothepatient.

labialbar-5 Indications:

1.Whenthemandibularteetharesoseverelyinclinedlinguallyastopreventtheuseoflingualmajorconnector.

.contraindicatedexistandtheirremovalis2.Whenlargelingualtori

Design:

1.Itisahalfpearshapedbar,runsacrossthemucosalabialtotheanteriorteeth.

2.Labialvestibuleshouldbeadequatetoallowthesuperiorbordertobeplacedatleast3mmbelowthefreegingivalmargins. 3.Reliefisrequiredbeneaththebar.

:Advantages

1-itsolvedtheproblemoflinguallyinclinedteeth&avoidsurgicalinterventiontoremovelargelingualtori

-:Disadvantages

lackofrigidity-1

leastcomfortabletopatient.-2

Tikrit University College of Dentistry – Dr. Reem Ahmed Shehab Lec-6- prosthodontics 3rd class

cden.tu.edu.iq