repair re line re base

8/3/2019 Repair Re Line Re Base

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Repair, relining and rebasingRepair, relining and rebasing

Dr. Amal Fathy KaddahDr. Amal Fathy KaddahProfessor of Prosthodontic,Professor of Prosthodontic,

Faculty of Oral &Dental Medicine,Faculty of Oral &Dental Medicine,Cairo UniversityCairo University

www.egydental.comwww.egydental.com


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First Steps In Making A Denture

Primary impression

Diagnostic cast

Custom tray

Final impression

Master cast


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Impression TechniquesImpression TechniquesPrimary impressionsPrimary impressions

Conventional techniquesConventional techniques

Template techniquesTemplate techniques

Definitive impressionsDefinitive impressionsII-- Conventional techniquesConventional techniques

IIII-- Selective pressure techniquesSelective pressure techniques

IIIIII-- Functional techniquesFunctional techniques

IVIV-- Reline and rebase techniquesReline and rebase techniques

(including secondary template impressions).(including secondary template impressions).


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Complete DenturesComplete Dentures


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Repair of Complete

Dentures


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Dentures may fracture

during function dropped on hard

surface

Key of repair = accurate reassembling

& alignment of the broken parts in theiroriginal position.


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Classification of fractured dentures

I) According to location of fracture

Midline fracture Any part fracture


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II) According to extent of fracture

With broken ormissing part &/or

teeth

Without broken ormissing part &/or

teeth


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IV) According to cause of fracture

Operator Patient

III) According to timing of fracture

Early fracture Delayed fracture


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Midline fracture(mainly in maxillary dentures)

Causes:

1) No or insufficient relief in the midline. (M.P.R.)(Early fracture)

2) Ridge resorption with loss of relief effect. (Delayedfracture)


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Procedures for repair of midline fracture:

Broken parts areassembled & fixed

together with stickywax on the polishedsurface.

Assembled parts maybe strengthened withburs or plastic sticks.


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Any undercut on the

fitting surface is blocked

out with wax or clay.

The fitting surface is

painted with separating

medium.

Procedures for repair of midline fracture:


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Stone plaster is pouredinto the fitting surface.

After stone setting, thedenture is removed fromthe cast and cleaned fromany traces of sticky wax.

Fractured edges arereduced, widened (8-10mm) along the fractureline and beveled towardsthe polished surface to

increase bonding surfacearea. Dove tail cuts may bemade to strengthen therepair joint.


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The cast is painted with separating

medium and the denture is secured to

the cast with rubber bands. Self cure A.R. is applied to the

modified fracture area until the area is

overfilled.

N.B. An alternate method is to waxand contour the fracture line to the

desired form using base plate wax,

followed by flasking, wax elimination,packing with self cure A.R. and placing

in the flask under press for 2 hrs.

Deflasking, finishing and polishing is

then done in the usual manner.


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Relief of the median palatineRelief of the median palatine

raphea.raphea.

Reline if needed.Reline if needed.

Remake in some cases.Remake in some cases.


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Main cause is falling on the ground or the sinkduring cleaning.

Types:

I- Fracture with no missing part

Repaired as mentioned.

Any part fracture


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II- Fracture with missing or lost part

Procedures:

An impression is madewith the denture placed

in patient mouth. After pouring the cast,either self cure A.R. isapplied to replace themissing part, or wax is

added and carved toresemble the brokendenture part, followed byflasking, packing, curing,

finishing & polishing.


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Fractured teeth are

cut away with burs. On the lingual side,enough acrylic isremoved and dovetailed.

Teeth of same size,shape & shade arepositioned in properalignment and waxedwith base plate wax.

III- Fracture with broken or missingteeth

Procedures:


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A plaster index (key) is madeto record & secure the positionof waxed teeth. Teeth to be repaired areremoved together with all waxaround them.

Teeth are then put back exactlyin their original position aided byplaster key. Self cure acrylic resin is addedfrom the lingual side until repair

area is over built. It is thencovered with tin foil. After curing, the index isremoved and the denture is

finished and polished.


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Def: Resurfacing or correction of dentureadaptation to underlying tissues by the addition ofa new resin material to its fitting surface withoutchanging its occlusal relation.

Relining of Complete Dentures

AdditionAddition ofMaterial to the tissue side of aofMaterial to the tissue side of a

denture to improve its adaptation to thedenture to improve its adaptation to thesupporting mucosa.supporting mucosa.


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Reline IndicationsReline Indications

Loss of retentionLoss of retention

InstabilityInstability

Food under dentureFood under denture

Abused mucosaAbused mucosa

Whenever the denture loses or has poor adaptation to theunderlying tissues, while all other factors as occlusion,esthetics, centric relation, V.D.O. and denture base

material are satisfactory.


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Reline: General ConsiderationsReline: General Considerations

Optimal tissue healthOptimal tissue health

Reasonable CR/COReasonable CR/CO

Adequate vertical dimensionAdequate vertical dimension

Adequate peripheral extensionsAdequate peripheral extensions


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Denture preparation: Any undercuts are removedfrom the denture base. Peripheral extensions are

checked and adjusted. Borders are reduced andsquared to provide a definiteedge for addition of newresin material.

Procedures: Patient is instructed to leave his denture out ofhis mouth at least 48 hrs to allow for recovery oftissues and reduce irritation caused by ill-fitteddenture.


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A hole is made in the palatalsurface to allow escape of

excess impression material.Slight reduction in the fittingsurface may be done to createsome space for the impression

material.

Border tracing & newimpressions are made undercentric occlusion to maintain

occlusal relationship.

The denture with impressionmaterial is boxed and pouredinto stone.


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. The denture is flasked, and the old resin material isthoroughly cleaned and roughened.


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. New acrylic resin material is packed, and the

denture is cured in pressure curing unit containingwater at 45c for 20 min. to prevent porosity of newresin material and warpage of the old resin material(release of internal stresses).

. Finishing and polishing is done in the usual manner.


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N.B.

When both upper and lower dentures need relining,lower denture should be completed first. The upper

may be relined against a stable lower denture.The denture should be clinically remounted toperfect the occlusion.


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Evaluate DenturesEvaluate Dentures


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Is Reline necessary????Is Reline necessary????

If after modifications, theIf after modifications, the fit and bitefit and biteseem improved, let the patient try theseem improved, let the patient try the

denture for one weekdenture for one weekif there is noif there is noimprovement, then reline.improvement, then reline.


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Is reline Necessary?Is reline Necessary?

Irritation of Peripheral Borders

Overextension


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Is reline Necessary?Is reline Necessary?

Overextended borders

Borders corrected


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Is reline necessary?Is reline necessary?

Error in CO on oneError in CO on oneside, will break theside, will break the

seal on the oppositeseal on the oppositesideside


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Is reline necessary?Is reline necessary?

Correct eccentric excursions


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DiagnosisDiagnosis--OcclusalOcclusal

disharmonydisharmony

1.1. Loss of stability and retentionLoss of stability and retention2.2. Irritation and inflammation on oneIrritation and inflammation on one

sideside

3.3. Teeth stained on one sideTeeth stained on one side


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Reline ContraindicationsReline Contraindications

1.1. Worn out denturesWorn out dentures

2.2. Vertical dimension loss greater thanVertical dimension loss greater than 77mmmm

3.3. Significant mucosal inflammationSignificant mucosal inflammation

4.4. Poor denture estheticsPoor denture esthetics

5.5. Denture related speech problemsDenture related speech problems


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ContraindicationsContraindications

Severe tooth wear

Severe vertical overlap

with tooth wear (posterior

tooth concept)Severe occlusal wear (CD

evaluation)


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PrePre--requisites for reliningrequisites for relining

Recognition of abused tissues, withsuperimposed candidiasis.


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Initiate Tissue RecoveryInitiate Tissue Recovery

ProgramProgram Intermittent hot and cold rinsesIntermittent hot and cold rinses

Massage tissuesMassage tissues

Relieve pressure areasRelieve pressure areas

Correct faulty occlusions and dentureCorrect faulty occlusions and denturebordersborders

Minimize stress byMinimize stress by Soft dietSoft diet

Removal of denture at nightRemoval of denture at night

Use tissue conditionersUse tissue conditioners


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Complete Denture ExamComplete Denture Exam

Healthy Tissues!!Healthy Tissues!!


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CUDRelineCUDReline

1. Check extensions 2. Indicate amount of

peripheral reduction required

3. BorderReduction 4. Tissue Conditioner preparation:

Peripheral reduction + Tissue surface


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CUDRelineCUDReline

5. Border Molding

Completed6. Palatal surface vented

after B. M.

7. Seat denture until wash

comes through vents8. Final Impression


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CUDRelineCUDReline

Incorrect seating.Incorrect seating.Improper plane ofImproper plane of

orientation:orientation:Not contacting teethNot contacting teeth

Excess materialExcess material

No ventsNo vents

Place ZnO washPlace ZnO wash

Have patient closeHave patient closein CR.in CR.


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CUDRelineCUDReline

ZnO wash. Posterior

palatal seal area

using impression

wax

Trim

excess wax

beyond

anteriorline

Reline final

impression


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Final Impression with PVS Final Impression with Rubber base


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post palatal sealpost palatal seal

combinationcombinationIdentify inIdentify in

impression, beforeimpression, before

pouring it up.pouring it up.

Identify onIdentify onimpression soimpression sotechnician cantechnician can

scribe the sealscribe the seal


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CLDRelineCLDReline

Border

molding

completed

Complete

Denture method-

ZnO

Rubber Base

Reline


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RelineReline

Relined cast: Donot separate

Roughened

border to blend

new acrylic with

old. Wont show

finishing line

After

processing:Note junction

line


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RelineReline

Trimmed and polished


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Delivery of RelineDelivery of Reline

Examine:

Peripheral extensions


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Delivery of RelineDelivery of Reline

Pressure IndicatorPressure IndicatorPaste (PIP)Paste (PIP)

Ask the patient toAsk the patient tobite on cotton rollsbite on cotton rolls

forfor 55 min.min.


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LABORATORYREMOUNTINGLABORATORYREMOUNTING


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CLINICALREMOUNTINGCLINICALREMOUNTING


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Perfection of occlusionPerfection of occlusion


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Def: It is a process of readaptation of a denture tothe underlying tissues by replacing the denture

base material with a new one without changing itsocclusal relation.

Rebasing of Complete Dentures

Indications:

When the existing denture base is unsatisfactorye.g. stained, crazed or porous.


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Procedures: An impression is made withthe denture and a cast isobtained.

An occlusal and incisal index

of the teeth is made in plasterusing Hooper duplicator Theposts of the lower part of theduplicator are seated in theupper part to maintain the

relationship of the casts to theplaster index.


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The denture with the impression material are

removed from the cast.

Artificial plastic teeth are sectioned from thedenture and all base material around the teeth isremoved. (porcelain teeth are removed by

flaming)

Teeth are placed and held in position in the indexusing sticky wax on the labial and buccal surface.

A layer of base plate wax is placed over the ridgeof the cast.


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The upper part of the duplicator is closed and

denture teeth are waxed to the proper thicknessand contour to the cast.

The cast is removed, flasked and processed inthe usual manner.

After deflasking, the cast is reattached to theupper part of the duplicator to adjust any occlusalerrors.

Occlusion of rebased denture is furtherperfected by clinical remount.


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THANK YOUTHANK YOU

repair re line re base

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