Impression techniques for rpd/ implant dentistry course

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IMPRESSION TECHNIQUES FORIMPRESSION TECHNIQUES FOR
REMOVABLE PARTIALREMOVABLE PARTIAL
DENTURE PROSTHESISDENTURE PROSTHESIS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com
www.indiandentalacademy.comwww.indiandentalacademy.com

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CONTENTSCONTENTS
• INTRODUCTIONINTRODUCTION
• CLASSIFICATION OF IMPRESSION TECHNIQUESCLASSIFICATION OF IMPRESSION TECHNIQUES
• DIFFERENT FUNCTIONAL IMPRESSIONDIFFERENT FUNCTIONAL IMPRESSION
PROCEDURESPROCEDURES
• TECHNIQUES OF POURING THE ALTERED CASTTECHNIQUES OF POURING THE ALTERED CAST
IMPRESSIONIMPRESSION
• CONCLUSIONCONCLUSION
• BIBLIOGRAPHYBIBLIOGRAPHY

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 In removable partial dentures that are completelyIn removable partial dentures that are completely
tooth supported ( Class III and many IV arches ),tooth supported ( Class III and many IV arches ),
occlusal forces-transmitted to abutment teeth areocclusal forces-transmitted to abutment teeth are
directed vertically down the long axes of teethdirected vertically down the long axes of teeth
throughthrough occocclusal, incisal, or lingual rests .lusal, incisal, or lingual rests .
 EdeEdentulous ridges will not contribute to support ofntulous ridges will not contribute to support of
partial denture, because teeth absorb these forcespartial denture, because teeth absorb these forces
before the forces are transmitted to the residual ridgebefore the forces are transmitted to the residual ridge
INTRODUCTIONINTRODUCTION

44
 Since the denture base does not contribute to supportSince the denture base does not contribute to support
of the partial denture & the underlying mucosa andof the partial denture & the underlying mucosa and
bone are not subjected to functional forces, a tooth-bone are not subjected to functional forces, a tooth-
supported removable partial denture can besupported removable partial denture can be
constructed on a master cast made from a single,constructed on a master cast made from a single,
pressure-free impression that records the teeth & thepressure-free impression that records the teeth & the
residual ridge in their anatomic formresidual ridge in their anatomic form

55
• A thorough understanding of the impressionA thorough understanding of the impression
materials and impression methods leads to conclusionmaterials and impression methods leads to conclusion
that no single material can record both the anatomicthat no single material can record both the anatomic
form of the teeth and tissue in the dental arch and, atform of the teeth and tissue in the dental arch and, at
the same time, the functional form of the residualthe same time, the functional form of the residual
ridge. Therefore some secondary or correctedridge. Therefore some secondary or corrected
impression method must be needed.impression method must be needed.

66
• when the design of a Removable partial denturewhen the design of a Removable partial denture
includes unilateral or bilateral distal extensionincludes unilateral or bilateral distal extension
denture base, a simple impression procedure, one thatdenture base, a simple impression procedure, one that
records only the anatomic form of the residual ridge,records only the anatomic form of the residual ridge,
is not sufficient to produce the type of Removableis not sufficient to produce the type of Removable
partial denture that can preserve all of the remainingpartial denture that can preserve all of the remaining
oral tissues.oral tissues.

77
• Steiger and Boitel (1959), the resiliency of the tissueSteiger and Boitel (1959), the resiliency of the tissue
fitting surface of the denture base ranges fromfitting surface of the denture base ranges from 0.4 to0.4 to
2.0mm2.0mm, compared with the resiliency of, compared with the resiliency of 0.lmm0.lmm forfor
healthy periodontal tissues.healthy periodontal tissues.
• Tissue resiliency is thereforeTissue resiliency is therefore four to twenty timesfour to twenty times
more than the axial displace ability of the abutmentmore than the axial displace ability of the abutment
tooth (Steiger and Boitel, 1959).tooth (Steiger and Boitel, 1959).

88
• The problem of achieving successful function of aThe problem of achieving successful function of a
Removable partial denture is equilibrating thisRemovable partial denture is equilibrating this
resiliency differential between the relatively non-resiliency differential between the relatively non-
resilient periodontal ligament of the abutment toothresilient periodontal ligament of the abutment tooth
and the more resilient mucosa covering the residualand the more resilient mucosa covering the residual
ridge.ridge.

99
Factors influencing support of theFactors influencing support of the
distal extension basedistal extension base
• Quality of soft tissue covering edentulous ridgeQuality of soft tissue covering edentulous ridge
• Type of bone in the denture bearing areaType of bone in the denture bearing area
• Design of the prosthesisDesign of the prosthesis
• Amount of tissue coverage of denture baseAmount of tissue coverage of denture base
• Anatomy of the denture bearing areaAnatomy of the denture bearing area
• Fit of denture baseFit of denture base

1010
Objectives of dual impressionObjectives of dual impression
1) It records and relates the supporting tissues under1) It records and relates the supporting tissues under
uniform loading.uniform loading.
2) It distributes the load over as large area as possible.2) It distributes the load over as large area as possible.
3) Accurately delineate the peripheral extent of the3) Accurately delineate the peripheral extent of the
denture basedenture base

1111
IndicationsIndications
1. The dual impression technique1. The dual impression technique isis most often indicatedmost often indicated
for the distal extension ridge, usually forfor the distal extension ridge, usually for
mandibular ridge becausemandibular ridge because
- only a limited ridge area can be used as a stress- only a limited ridge area can be used as a stress
bearing area .bearing area .
- it is difficult to obtain the proper peripheral- it is difficult to obtain the proper peripheral
extension .extension .
- increased resiliency of the mucosa .- increased resiliency of the mucosa .
2. long span anterior edentulous ridge normally2. long span anterior edentulous ridge normally
including at least all the 6 anterior teeth, where theincluding at least all the 6 anterior teeth, where the
ridge must supply some support for the partialridge must supply some support for the partial
denture.denture. www.indiandentalacademy.comwww.indiandentalacademy.com

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Impression techniquesImpression techniques
• Physiologic impression techniquePhysiologic impression technique
- McLean and Hindels method- McLean and Hindels method
- The functional relining method- The functional relining method
- The fluid wax method- The fluid wax method
• Selected pressure techniqueSelected pressure technique

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1.The Physiologic Or Functional Impression1.The Physiologic Or Functional Impression
Technique:Technique:
This technique records the ridge positionThis technique records the ridge position
by placing an occlusal load on the impression tray asby placing an occlusal load on the impression tray as
the impression is being made.the impression is being made.

1414
• In short, these techniques produced a generalizedIn short, these techniques produced a generalized
displacement of the mucosa to a greater or lesserdisplacement of the mucosa to a greater or lesser
degree.degree.
• This displacement was intended to record the tissue inThis displacement was intended to record the tissue in
the configuration it would assume when occlusalthe configuration it would assume when occlusal
loading was applied to a partial denture in function.loading was applied to a partial denture in function.

1515
2.2. The Selected Pressure Impression:The Selected Pressure Impression:
Here there is not only the equalization of supportHere there is not only the equalization of support
between the abutment teeth and the soft tissue, butbetween the abutment teeth and the soft tissue, but
also have the added advantage of directing the forcesalso have the added advantage of directing the forces
to the portions of the ridge, that are most capable ofto the portions of the ridge, that are most capable of
withstanding the force.withstanding the force.
This is accomplished by providing relief in theThis is accomplished by providing relief in the
impression tray in selected areas and permitting theimpression tray in selected areas and permitting the
impression tray to contact the ridge in other areas.impression tray to contact the ridge in other areas.

1616
• In both the fluid wax functional impression techniqueIn both the fluid wax functional impression technique
and the selected pressure technique, an impression ofand the selected pressure technique, an impression of
the edentulous ridge is made using an impressionthe edentulous ridge is made using an impression
tray attached to the frame-work. The master cast istray attached to the frame-work. The master cast is
altered to accommodate the secondary impression,altered to accommodate the secondary impression,
and a corrected cast is generated.and a corrected cast is generated.
For this reason, the technique is often referred to asFor this reason, the technique is often referred to as
thethe Altered Cast Impression Technique or theAltered Cast Impression Technique or the
Corrected Cast Impression Technique.Corrected Cast Impression Technique.

1717
PHYSIOLOGIC IMPRESSIONPHYSIOLOGIC IMPRESSION
TECHNIQUE:TECHNIQUE:
• MCLEAN'S IMPRESSION TECHNIQUE:MCLEAN'S IMPRESSION TECHNIQUE:
They realized the need of recording the tissues of theThey realized the need of recording the tissues of the
residual ridge that would eventually support a distalresidual ridge that would eventually support a distal
extension denture base in the functional, orextension denture base in the functional, or
supporting form and then relating this functionalsupporting form and then relating this functional
impression to the remainder of the arch by means of aimpression to the remainder of the arch by means of a
second impression.second impression.

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1919
• For this dual impression a custom impression try wasFor this dual impression a custom impression try was
constructed over a preliminary cast of the arch and aconstructed over a preliminary cast of the arch and a
functional impression of the distal extension ridgefunctional impression of the distal extension ridge
was made, and then a hydrocolloid impression waswas made, and then a hydrocolloid impression was
made with the first impression held in its functionalmade with the first impression held in its functional
position with finger pressure.position with finger pressure.

2020
• DisadvantageDisadvantage
The greatest weakness of this technique was thatThe greatest weakness of this technique was that
finger pressure could not produce the same functionalfinger pressure could not produce the same functional
displacement of the tissue that biting force produced.displacement of the tissue that biting force produced.

2121
Hindel's Technique:Hindel's Technique:
Hindels and others developed special trays forHindels and others developed special trays for
reversible hydrocolloid for making the secondreversible hydrocolloid for making the second
impression, that is provided with holes, so that fingerimpression, that is provided with holes, so that finger
pressure could be applied through the tray as thepressure could be applied through the tray as the
hydrocolloid impression was made.hydrocolloid impression was made.
The main purpose of this technique was to relate anThe main purpose of this technique was to relate an
impression of the edentulous ridge to the teeth underimpression of the edentulous ridge to the teeth under
a form of functional loading.a form of functional loading.

2323
DisadvantagesDisadvantages
a) If the action of the retentive clasps of the partiala) If the action of the retentive clasps of the partial
denturedenture isis sufficient tosufficient to maintainmaintain the denture base inthe denture base in
relation to the soft tissuesrelation to the soft tissues inin the displaced orthe displaced or
functional form, interruption of blood circulationfunctional form, interruption of blood circulation
would ensure with possible adverse soft tissuewould ensure with possible adverse soft tissue
reactions and resorption of the underlying bone.reactions and resorption of the underlying bone.

2424
b) If the action of the retentive clasps was notb) If the action of the retentive clasps was not
sufficient to maintain that functional relationship ofsufficient to maintain that functional relationship of
the denture base to the soft tissue, the denture basethe denture base to the soft tissue, the denture base
will be occlusally positioned when the soft tissueswill be occlusally positioned when the soft tissues
are at rest.are at rest.
this results in premature contact of the artificialthis results in premature contact of the artificial
teeth, which may be objectionable to many patients.teeth, which may be objectionable to many patients.

2525
Functional Relining MethodFunctional Relining Method
• It consists of adding a new surface to the inner orIt consists of adding a new surface to the inner or
tissue side of the denture base.tissue side of the denture base.
• The procedure may be accomplished before theThe procedure may be accomplished before the
insertion of the partial denture, or it may be done at ainsertion of the partial denture, or it may be done at a
later date if the denture base no longer fits the ridgelater date if the denture base no longer fits the ridge
adequately because of bone resorptionadequately because of bone resorption

2626
To allow room for impressionTo allow room for impression
material between denture base &material between denture base &
ridge, space must be provided & isridge, space must be provided & is
got by adapting a soft metalgot by adapting a soft metal
spacer(Ash's No. 7metal),over thespacer(Ash's No. 7metal),over the
ridge on the cast before processingridge on the cast before processing
denture base.denture base.
After processing, the metal isAfter processing, the metal is
removed, leaving an even spaceremoved, leaving an even space
between the base and thebetween the base and the
edentulous ridgeedentulous ridge

2727
• The portion of the technique that introduces theThe portion of the technique that introduces the
greatest hazard is the reline impression procedure.greatest hazard is the reline impression procedure.
• The patient must keep the mouth partially openThe patient must keep the mouth partially open
throughout the procedure to permit appropriatethroughout the procedure to permit appropriate
tissue control and the required visual assessment.tissue control and the required visual assessment.

2828
• The actual impression forThe actual impression for
functional reline consists offunctional reline consists of
flowing low fusing modelingflowing low fusing modeling
plastic over the tissue surface ofplastic over the tissue surface of
denture base,heating,temperingdenture base,heating,tempering
and reseating several times untiland reseating several times until
accurate impression is got.accurate impression is got.
• Modeling plastic over ridge isModeling plastic over ridge is
relieved by scraping to 1 mm orrelieved by scraping to 1 mm or
entire thickness of modelingentire thickness of modeling
plastic from the crest of ridgeplastic from the crest of ridge
can be removedcan be removed

2929
• During border molding the patient must maintain theDuring border molding the patient must maintain the
mouth in amouth in a partially open positionpartially open position while the borderwhile the border
molding and impression are being accomplishedmolding and impression are being accomplished
because:because:
1. The border tissues, cheek, and tongue are thus best1. The border tissues, cheek, and tongue are thus best
controlled .controlled .
2. The relationship between the partial denture2. The relationship between the partial denture
framework and the teeth must be observed.framework and the teeth must be observed.

3030
Making the final impressionMaking the final impression
1)Usually free flowing ZnO eugenol paste is used1)Usually free flowing ZnO eugenol paste is used
2)If undercuts are present on the ridge,light bodied2)If undercuts are present on the ridge,light bodied
polysulphide or silicone rubber may be usedpolysulphide or silicone rubber may be used
Functional reline method has the advantage that the amountFunctional reline method has the advantage that the amount
of soft tissue displacement can be controlled by amount ofof soft tissue displacement can be controlled by amount of
relief given to modeling plastic before making finalrelief given to modeling plastic before making final
impression. Greater the relief,less will be the tissueimpression. Greater the relief,less will be the tissue
displacementdisplacement

3131
• DisadvantageDisadvantage
The main problems that arise are caused by failure toThe main problems that arise are caused by failure to
maintain the correct relationship between themaintain the correct relationship between the
framework and the abutment.framework and the abutment.
Failure to achieve accurate occlusal contact followingFailure to achieve accurate occlusal contact following
reline procedure.reline procedure.
As in all other reline procedures occlusalAs in all other reline procedures occlusal
discrepancies must be correcteddiscrepancies must be corrected

3232
• When the acrylic resin tray material was adapted toWhen the acrylic resin tray material was adapted to
the framework on the master cast, no relief providedthe framework on the master cast, no relief provided
between the ridge and the tray so that material wouldbetween the ridge and the tray so that material would
be securely attached to the latticework and so that thebe securely attached to the latticework and so that the
tray would be stabilized during the border moldingtray would be stabilized during the border molding
procedure.procedure.
• It is now necessary to provide relief under theIt is now necessary to provide relief under the
impression material. It is at this point in theimpression material. It is at this point in the
procedure that the technique for the fluid waxprocedure that the technique for the fluid wax
functional impressionfunctional impression differsdiffers from that of the selectedfrom that of the selected
pressure impression.pressure impression.

3333
Fluid Wax Functional ImpressionFluid Wax Functional Impression
TheThe objectivesobjectives of the technique are:of the technique are:
• To obtain maximum extension of the peripheralTo obtain maximum extension of the peripheral
borders of the denture base while not interfering withborders of the denture base while not interfering with
the function of movable border tissues.the function of movable border tissues.
• To record the stressbearing areas of the ridge inTo record the stressbearing areas of the ridge in
theirtheir functional formfunctional form, and to record nonpressure, and to record nonpressure
bearing areas in theirbearing areas in their anatomic form.anatomic form.

3434
• The fluid wax impression is made with theThe fluid wax impression is made with the openopen
mouth techniquemouth technique so that there is less danger of overso that there is less danger of over
displacement of ridge tissue by occlusal or verticaldisplacement of ridge tissue by occlusal or vertical
forces.forces.

3636
• The term fluid wax is used to denote waxes that areThe term fluid wax is used to denote waxes that are
firm at room temperature and have the ability to flowfirm at room temperature and have the ability to flow
at mouth temperature.at mouth temperature.
• The most frequently used fluid waxes are Iowa Wax,The most frequently used fluid waxes are Iowa Wax,
‫٭‬‫٭‬ Iowa Wax ,Iowa Wax , developed by Dr. Smith at thedeveloped by Dr. Smith at the
University of Iowa,University of Iowa,
‫٭‬‫٭‬ Korrecta Wax No.4,Korrecta Wax No.4, developed by Dr.O.C anddeveloped by Dr.O.C and
S.G. Applegate at the Universities of Michigan andS.G. Applegate at the Universities of Michigan and
Detroit, respectively.Detroit, respectively.
• Korrecta Wax No.4 is slightly more fluid than IowaKorrecta Wax No.4 is slightly more fluid than Iowa
Wax.Wax.

3737
• The key to the use of fluid wax lies in twoThe key to the use of fluid wax lies in two
areas:areas:
- spacespace
- time- time
• SpaceSpace refers to the amount of reliefrefers to the amount of relief
provided between the impression tray and theprovided between the impression tray and the
edentulous ridge.edentulous ridge.
• Relief between the tray and the ridge ofRelief between the tray and the ridge of 1 to1 to
2 mm2 mm is the desired amount.is the desired amount.

3838
• The borders must be short of all movable tissues, butThe borders must be short of all movable tissues, but
not more than 2 mm shortnot more than 2 mm short because the fluid wax doesbecause the fluid wax does
not have sufficient strength to support itself beyondnot have sufficient strength to support itself beyond
that distance.that distance.
Each time the tray is introduced into the mouth, itEach time the tray is introduced into the mouth, it
must remain in place 5 to 7 minutesmust remain in place 5 to 7 minutes..
- To allow the wax to flow and- To allow the wax to flow and
- To prevent buildup of pressure under the tray- To prevent buildup of pressure under the tray
with resulting distortion or displacement of the tissue.with resulting distortion or displacement of the tissue.

3939
• The clinical technique for the use of the fluidThe clinical technique for the use of the fluid
wax calls for a water bath maintained at 51˚cwax calls for a water bath maintained at 51˚c
to 54°C (125˚ to 130˚ F) into which ato 54°C (125˚ to 130˚ F) into which a
container of the wax is placed.container of the wax is placed.
• At this temperature the wax becomes fluid.At this temperature the wax becomes fluid.
• The wax is painted on the tissue side of theThe wax is painted on the tissue side of the
impression tray with a brush.impression tray with a brush.
procedureprocedure

4040
• The impression surface which contacts the tissue willThe impression surface which contacts the tissue will
be glossy and the surface which does not come inbe glossy and the surface which does not come in
contact with the tissue will be dullcontact with the tissue will be dull
• Wax is added on the dull surface and the impressionWax is added on the dull surface and the impression
is placed back for 5 min in the mouth .is placed back for 5 min in the mouth .
• Procedure is repeated till the impression is completed.Procedure is repeated till the impression is completed.
The finished impression must be handled carefully,The finished impression must be handled carefully,
and the new cast poured as soon as possible becauseand the new cast poured as soon as possible because
the wax is fragile and subject to distortion.the wax is fragile and subject to distortion.

4141
DisadvantagesDisadvantages
• The procedure is time consuming.The procedure is time consuming.
• If the time periods are not followed accurately,If the time periods are not followed accurately,
than impression with excessive tissuethan impression with excessive tissue
displacement will result.displacement will result.

4242
Selected pressure impression techniqueSelected pressure impression technique
TheThe objectivesobjectives of the technique are:-of the technique are:-
• To direct more force to those portions of the ridgeTo direct more force to those portions of the ridge
which is able to absorb the stress without adversewhich is able to absorb the stress without adverse
response.response.
• Protect the areas of the ridge which is least able toProtect the areas of the ridge which is least able to
absorb force.absorb force.

4444
• Areas where relief is provided will be least displaced asAreas where relief is provided will be least displaced as
the impression is recorded . In those areas of the tray wherethe impression is recorded . In those areas of the tray where
relief is not provided greater displacement of the underlyingrelief is not provided greater displacement of the underlying
mucosa will occurmucosa will occur
• Mandibular Arch Posterior regionMandibular Arch Posterior region
• 1) Crest of Arch – Not a prssure bearing area –Hence1) Crest of Arch – Not a prssure bearing area –Hence
relievedrelieved
• 2)Buccal Shelf – Primary stress bearing area – hence slight2)Buccal Shelf – Primary stress bearing area – hence slight
relief is only provided hererelief is only provided here
• 3)Lingual slope – Principally resists horizontal or rotational3)Lingual slope – Principally resists horizontal or rotational
forces – Relief is provided same as that of Buccal shelfforces – Relief is provided same as that of Buccal shelf
area .(i.e., Minimal relief)area .(i.e., Minimal relief)

4545
• The end result of this selected pressure impression isThe end result of this selected pressure impression is
that the denture base made impression will be closelythat the denture base made impression will be closely
adapted to and in firm contact with the tissueadapted to and in firm contact with the tissue
covering the buccal shelf area of the edentulous ridge.covering the buccal shelf area of the edentulous ridge.
• The ridge crest on the other hand is lightly adapted toThe ridge crest on the other hand is lightly adapted to
the tissue and the effects of occlusal loading will bethe tissue and the effects of occlusal loading will be
less in this area.less in this area.

4646
Techniques for pouring the correctedTechniques for pouring the corrected
cast impressioncast impression
• Boxing corrected cast impression with plaster/pumiceBoxing corrected cast impression with plaster/pumice
mix and waxmix and wax
• Beading and boxing with waxBeading and boxing with wax
• Beading with wax and the two stage pourBeading with wax and the two stage pour
• North carolina techniqueNorth carolina technique

4848
Procedure
11. A metallic paste impression is received in the
laboratory. Remove impression material from the
framework in areas that contact the teeth.

4949
2. Trim the master cast so that the functional impression
can be poured in correct relationship to the remaining
teeth.

5050
3. Seat the framework on the cast, and inspect it for
contact between the functional impression and the cast.
If contact is present, the cast must be trimmed until
clearance is present.

5151
4. Cut retention grooves into the areas of the cast that
will be corrected when the functional impression is
poured

5252
5. Adapt and seal beading wax 2 to 3 mm above the
borders of the functional impression

5353
6. Seat the framework on the cast, and secure it in
position with sticky wax

5454
7.7. Seal the leading edge of the impression to the cast to
prevent dental stone from flowing onto the teeth
when the cast is poured.

5555
8. Use strips of base plate wax to complete the boxing
of the impression on the buccal and lingual aspects

5656
9. A tight seal of beading and boxing wax is critical in this
pouring method and is difficult to attain. Test the
completeness of the seal by pouring clear slurry water
into the boxed impression. A difficult area to seal is the
relief area under the major connector.

5757
10. Place the cast and impression in clear slurry water to
soak for 4 to 5 minutes in preparation for pouring the
corrected cast.

5858
11. Measure and mix the improved dental stone. Pour the
boxed impression by adding small increments of stone
and using light vibration. Sufficient stone must be used
to support the heel of the cast.

5959
12. Remove the boxing and luting materials from the
corrected cast. Shape the cast on a model trimmer.

6060
13.13. Soften the impressionSoften the impression material in warm water, andmaterial in warm water, and
remove the framework and impression tray from theremove the framework and impression tray from the
corrected cast.corrected cast.

6161
14. Burn the impression tray off the framework and
place it on the cast. Smooth the land area of the cast,
and the corrected cast procedures is complete.

6262
Altered cast techniqueAltered cast technique
• Master cast must beMaster cast must be
modified in preparationmodified in preparation
for altered castfor altered cast
procedure. Broken lineprocedure. Broken line
indicates proposed castindicates proposed cast
modifications formodifications for
bilateral altered castbilateral altered cast
procedureprocedure

6363
• Master cast afterMaster cast after
modification, Dovetailsmodification, Dovetails
have been prepared tohave been prepared to
permit mechanicalpermit mechanical
interlocking of castinterlocking of cast
segmentssegments

6464
• Framework seated onFramework seated on
modified master castmodified master cast
and affixed usingand affixed using
modelling plastic tomodelling plastic to
minimize displacementminimize displacement
and distortionand distortion
• Assembly is inverted inAssembly is inverted in
preparation for rimmingpreparation for rimming
and boxing proceduresand boxing procedures

6565
• Utility wax is used toUtility wax is used to
rim the impression.it isrim the impression.it is
located 2-3 mm fromlocated 2-3 mm from
impression and 3-4mmimpression and 3-4mm
peripherally. Boxingperipherally. Boxing
wax added to form awax added to form a
watertight vertical wall .watertight vertical wall .
Freshly mixed dentalFreshly mixed dental
stone is then introducedstone is then introduced

6666
• After the stone hasAfter the stone has
gained sufficientgained sufficient
strength ,the correctedstrength ,the corrected
cast is recovered andcast is recovered and
trimmedtrimmed

6868
For the production of accurate master cast the
impression technique far out weighs the selection
of the impression material.
No available knowledge of the person making the
impression material will produce results greater
than the skill and knowledge of the person
making the impression.

6969
““ Good technique pays off ” is not merely a
motto to hang on a wall but these are words
of wisdom. Good technique will indeed result
in better treatment and improved patient care.

7070
BIBLIOGRAPHYBIBLIOGRAPHY
1.1. Glossary of Prosthodontic Terms -8 th Edn, 2005.Glossary of Prosthodontic Terms -8 th Edn, 2005.
2.2. Stewart, Rudd, Kuebker : Clinical RemovableStewart, Rudd, Kuebker : Clinical Removable
Partial Prosthodontics.Partial Prosthodontics.
3.3. Kenneth D Rudd, Morrow: Dental Lab, ProcedureKenneth D Rudd, Morrow: Dental Lab, Procedure
for Removable Partial Dentures.for Removable Partial Dentures.
4.4. McCracken’s : Removable Partial Prosthodontics -McCracken’s : Removable Partial Prosthodontics -
11 edition11 edition

7171
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