SlideShare une entreprise Scribd logo
1  sur  70
IMPRESSION PROCEDURES
FOR DISTAL EXTENSION
BASES

www.indiandentalacademy.com
INDIAN DENTAL ACADEMY
Leader in continuing dental education
www.indiandentalacademy.com

www.indiandentalacademy.com
Contents
 INTRODUCTION
 DEFINITIONS
 RPD IMPRESSION Vs C D IMPRESSION
 PRIMARY IMPRESSION
 FINAL IMPRESSION METHODS
 Mc LEAN’S TECHNIQUE
 HINDEL’S TECHNIQUE
 SELECTIVE PRESSURE TECHNIQUE
 FUNCTIONAL RELINING TECHNIQUE
 FLUID WAX TECHNIQUE
 ALTERED CAST TECHNIQUE

MODIFICATION
 REVIEW OF LITERATURE
 CONCLUSION
 REFERENCES

www.indiandentalacademy.com
Definitions
 Impression
 A negative likeness or copy in reverse of the surface
of an object ; imprint of teeth and adjacent structures
for use in dentistry.
GPT – 8

Partial denture impression
 A negative likeness of a part or all of a partially

edentulous arch - GPT – 8

www.indiandentalacademy.com
 An impression of partially edentulous arch

must record accurately the anatomic form
of teeth and surrounding tissues.

 Unless the cast upon which the prosthesis

is to be constructed is an exact replica of
mouth, the prosthesis can‘t be expected to
fit properly and accurate cast can be
obtained only from an accurate impression.

www.indiandentalacademy.com
Impression trays

A receptacle in to which suitable impression material is
placed to make negative likeness
OR
A device that is used to carry, confine and control
impression material while making an impression.

www.indiandentalacademy.com
www.indiandentalacademy.com
Impression trays can be classified broadly
in to stock trays and custom trays
Stock Trays
Stock trays for partially edentulous patients may
be perforated to retain the impression material or
they may be constructed with a rimlock for this
purpose.
Another type of stock tray designed for the
reversible type of hydrocolloid is water cooled
trays. It contains tubes through which water can
be circulated for purpose of cooling the tray.
www.indiandentalacademy.com
Disadvantages: STOCK TRAY
a. The peripheral borders cannot be
accurately recorded.
b. Considerably more bulkier than a custom
tray.

www.indiandentalacademy.com
Custom impression trays:
a. Peripheral borders can be precisely recorded in
the impression
b. Thickness of impression material can be
controlled.

www.indiandentalacademy.com
C. Well fitted tray will better support the
impression in the palate, then avoiding even
present danger of material slumping in vital
areas.
Custom trays are sometimes needed for mouths that are
abnormally or of unusual configuration.

www.indiandentalacademy.com
Plaster
Non-elastic

Compound

Impression
Materials

Waxes
Impression
Materials

ZnO - Eugenol

Aqueous
Hydrocolloids
Elastic

Agar (reversible)
Alginate (irreversible)
Polysulfide

Non-aqueous
Elastomers

Silicones
Polyether

www.indiandentalacademy.com

Condensation
Addition

O’Brien Dental Materials & their Selection 1997
RPD IMPRESSION Vs

o

COMPLETE DENTURE

partial denture
impression records
relative soft
yielding tissues (the
oral mucosa) as well
as a hard unyielding
substance (the
remaining teeth).

IMPRESSION

The complete denture

impression records the
edentulous mucosa with
underlying bone only

www.indiandentalacademy.com
Removable partial denture impression need to
record the teeth that are irregular in contour as
well as varying in their vertical relations to
occlusal plane.
The chosen impression material must be capable
of recording the tissue contours as accurately as
possible without distortion, which occurs as
impression is withdrawn.

www.indiandentalacademy.com
PRIMARY IMPRESSION
Objective:
To obtain an impression of all the standing teeth and
denture - supporting tissues of each jaw from which
study casts may be prepared.

www.indiandentalacademy.com
The purpose of the study casts are:

To enable special trays and occlusion rims to be
constructed if necessary.
To examine the occlusion in detail on an articulator.
By use of a surveyor, to plan the path of insertion of
the proposed denture, arrive at a tentative design
and plan any mouth preparation.

www.indiandentalacademy.com
www.indiandentalacademy.com
Factors Influencing Support of Distal Extension
Base
Quality of Soft tissue covering edentulous ridge
Type of bone making up denture-bearing area
Design of partial denture
Amount of tissue coverage of denture base
Amount of occlusal forces
Denture bearing area
Fit of the denture base

www.indiandentalacademy.com
Impression Methods:

There are basically two dual impression techniques.
 The physiologic impression techniques that discussed are as

follows:

 Mc Lean’s and Hindel’s methods,
 the functional relining method, and
 the fluid wax method.

 Selected pressure impression

www.indiandentalacademy.com
www.indiandentalacademy.com
 The need for physiologic impressions was first recognized by

McLean

 For this dual impression a custom impression tray was

constructed over a preliminary cast of the arch

 A function impression of the distal extension ridge was

made, and then hydrocolloid impression was made with the
first impression held in its functional position with finger
pressure

www.indiandentalacademy.com
www.indiandentalacademy.com
o The greatest weakness of the technique was that finger

pressure could not produce the same functional
displacement of the tissue that biting force produced.

o Many variations of this technique have been developed and

advocated, but all require some form of finger loading
pressure as the second impression is made.

www.indiandentalacademy.com
www.indiandentalacademy.com
• Hindels and other developed irreversible

hydrocolloid trays for the second impression that
were provided with holes so that finger pressure
could be applied through the tray as the
hydrocolloid impression was made.

www.indiandentalacademy.com
www.indiandentalacademy.com
o The main change that Hindels introduced

to McLean ‘s original technique was that

o The impression of the edentulous ridge was

not made under pressure but was an
anatomic impression of the ridge at rest
made with a free flowing zinc oxide eugenol
paste.

www.indiandentalacademy.com
o As the hydrocolloid second impression was being

made, finger pressure was applied through the
holes in the tray to the anatomic impression.

o The pressure had to be maintained until the

alginate was completely set.

www.indiandentalacademy.com
The main purpose of these techniques was to relate an
impression of the edentulous ridge to the teeth under
a form of functional loading.

www.indiandentalacademy.com
o A disadvantage of these techniques was that if the action of

the retentive clasps of the partial denture is sufficient to
maintain the denture base in relation to the soft tissues in
the displaced or functional form,

o Interruption of blood circulation would ensue, with possible

adverse soft tissue reaction and resorption of the underlying
bone.

www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
o

Most methods of obtaining a physiologic impression for
support of a distal extension denture base accomplish the
impression procedure before completion of the denture,
usually following the construction of the framework.

o

It is possible, however, to obtain the same results after the
partial denture has been completed.

o

The technique is referred to as a functional reline. It
consists of adding a new surface to the inner, or tissue, side
of the denture base.

www.indiandentalacademy.com
o The procedure may be accomplished before the insertion of

the partial denture, or it may be done at a later date because
of bone resorption, the denture base no longer fits the ridge
adequately.

o Although the functional reline has many advantages, and for

correcting the fit of denture base that has been worn for a
period of time is essential, it does present many difficulties.

www.indiandentalacademy.com
o The main problems that arise are caused by failure to

maintain the correct relationship between the framework
and the abutment teeth during the impression procedure
and failure to maintain accurate occlusal contact following
the reline.

www.indiandentalacademy.com
o To allow room for the impression material between the denture

base and the ridge, space must be provided.

o One of the most accurate methods of ensuring uniform space

for the impression is to adapt a soft metal spacer over the ridge
on the cast before processing the denture base.

o After processing, the metal is removed leaving an even space

between the base and the edentulous ridge.

www.indiandentalacademy.com
www.indiandentalacademy.com
The patient must maintain the mouth in a partially open
position while the border molding and impression are being
accomplished because:
1.The border tissues, cheek, and tongue are thus best controlled
and

2.The relationship between the partial denture frame work and th
teeth must be observed.

www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
The functional reline method has the advantage that the
amount of soft tissue displacement can be controlled by the
amount of relief given to the modeling plastic before the
final impression is made. The greater the relief the less will
be the tissue displacement.

www.indiandentalacademy.com
www.indiandentalacademy.com
The fluid wax impression may be used to make a
reline impression for an existing partial denture or to
correct the distal extension edentulous ridge portion
of the original master cast.

www.indiandentalacademy.com
OBJECTIVES
To obtain maximum extension of the peripheral
borders of the denture base while not interfering
with the function of movable border tissues.
To record the stress bearing areas of the ridges in
their functional form.
To record non pressure bearing areas in their
anatomic form.

www.indiandentalacademy.com
The fluid wax impression is made with the open
mouth technique so that there is less danger of
over displacement of ridge tissue by occlusal or
vertical forces.

www.indiandentalacademy.com
The term fluid wax is used to denote waxes that are
firm at room temperature and have the ability to flow
at mouth temperature.

www.indiandentalacademy.com
The most frequently used fluid waxes are Iowa wax,
developed by Dr.Smith at the University of Iowa, and
Korrecta Wax No. 4, developed by Dr. 0. C. Applegate
and S. G Applegate at the Universities of Michigan
and Detroit, respectively.
Korrecta wax no. 4 is slightly more fluid than Iowa
wax.

www.indiandentalacademy.com
The key to the use of fluid wax lies in two areas: space
and time.
Space refers to the amount of relief provided
between the impression tray and the edentulous
ridge. :1 to 2 mm is desired.
Each time the tray is introduced into the mouth, it
must remain in place 5 to 7 minutes to allow the wax
to flow and to prevent buildup of pressure under the
tray with resulting distortion or displacement of the
tissue.

www.indiandentalacademy.com
o The clinical technique for the use of the fluid wax calls

for the water bath maintained at 51° to 54° C into which
a container of the wax is placed.

o At this temperature the wax becomes fluid. The wax is

painted on the tissue side of the impression tray with a
brush.

www.indiandentalacademy.com
www.indiandentalacademy.com
The borders must be short of all movable tissue, but
not more than 2 mm short because the fluid wax does
not have sufficient strength to support itself beyond
that distance.

www.indiandentalacademy.com
Inaccuracies will develop if the wax is extended
beyond that length.
Originally a harder wax, Korrecta Wax no:1 was used
to support the softer No.4 wax if extension beyond
that length was needed. The no.1 wax however, is no
longer available.

www.indiandentalacademy.com
o The wax is painted on the surface of the tray to a depth

slightly greater than the amount of relief provided. The tray is
seated in the mouth.

o The patients must remain with the mouth approximately half

open for about 5 minutes.

o The tray is removed, and the wax examined for evidence of

tissue contact. Where tissue contact is present the wax surface
will be dull.

www.indiandentalacademy.com
o

If needed additional wax is painted on those areas not in
contact with the tissue. The tray must remain in the mouth a
minimum of 5 minutes after each addition of wax.

o The peripheral extensions are developed by tissue movements

by the patient.

o For the buccal and distobuccal extension in a mandibular

impression the patient must move to a wide- open-mouth
position.

o This will activate the buccinator muscle and pterygomandibular

raphe and produce the desired border anatomy.

www.indiandentalacademy.com
o For the proper lingual extension for a mandibular

impression the patient must thrust the tongue into the cheek
opposite the side of the arch being border molded.

o The distolingual extension is obtained by having the patient

press the tongue forward against the lingual surface of the
anterior teeth.

www.indiandentalacademy.com
These movements must be repeated a number
of times after the impression has been in the
mouth long enough for the wax to have
softened sufficiently to flow.

www.indiandentalacademy.com
o When the impression evidences complete tissue

contact and when the anatomy of the limiting border
structure is evident, the impression should be
replaced in the mouth for 12 minutes.

o This final time to be certain that the wax has

completely flowed and released any pressure that
may be present.

www.indiandentalacademy.com
www.indiandentalacademy.com
The finished impression must be handled
carefully and the new cast poured as soon as
possible because the wax is fragile and subject
to distortion.

www.indiandentalacademy.com
The fluid wax impression technique can produce an
accurate impression if the technique is properly
executed The procedure is time consuming, but if the
time periods are not followed accurately, an
impression with excessive tissue displacement will
result.

www.indiandentalacademy.com
Selective Pressure technique

www.indiandentalacademy.com
This impression technique attempts to direct more

force to those portions of the ridge able to absorb the
stress without adverse response

Tissue surface of the tray is selectively relieved .

www.indiandentalacademy.com
Impression materials
Zinc-oxide Eugenol paste
Rubber base materials

www.indiandentalacademy.com
Impression technique
Border molding
Making impression with the ZOE or Rubber base

materials
The critical point is to determine visually that all rest
and indirect retainers are completely seated

www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
Corrected cast

www.indiandentalacademy.com
Technique
1. Fashioning custom acrylic resin impression tray to retention
lattice work of removable partial denture.
2. Developing denture base impression on these trays.
3. Removing edentulous ridge from master cast.
4. Securing framework with developed bases to master cast.
5. Pouring the impression with dental stone.

www.indiandentalacademy.com
www.indiandentalacademy.com
www.indiandentalacademy.com
Leader in continuing dental education

www.indiandentalacademy.com

Contenu connexe

Tendances

Surveyor and technique of Surveying in Removable partial denture
Surveyor and technique of Surveying in Removable partial dentureSurveyor and technique of Surveying in Removable partial denture
Surveyor and technique of Surveying in Removable partial dentureFarah Fahad
 
Clinical and laboratory remoutning
Clinical and laboratory remoutningClinical and laboratory remoutning
Clinical and laboratory remoutningDr.Pallavi Chavan
 
Impression techniques in fpd
Impression techniques in fpdImpression techniques in fpd
Impression techniques in fpdApurva Thampi
 
Tooth preparation for Metal ceramic crowns.
Tooth preparation for Metal ceramic crowns.Tooth preparation for Metal ceramic crowns.
Tooth preparation for Metal ceramic crowns.srinivaslalluri
 
Functionally Generated Pathway
Functionally Generated Pathway Functionally Generated Pathway
Functionally Generated Pathway Sabnoor Aujla
 
Provisional restoration
Provisional restorationProvisional restoration
Provisional restorationSk Aziz Ikbal
 
impression techniques of complete denture
impression techniques of complete dentureimpression techniques of complete denture
impression techniques of complete dentureakanksha arya
 
RPI & RPA system
RPI & RPA systemRPI & RPA system
RPI & RPA systemJehan Dordi
 
Impression procedures for compromised ridges/cosmetic dentistry courses
Impression procedures for compromised ridges/cosmetic dentistry coursesImpression procedures for compromised ridges/cosmetic dentistry courses
Impression procedures for compromised ridges/cosmetic dentistry coursesIndian dental academy
 
Secondary impression in complete denture CD
Secondary impression in complete denture CDSecondary impression in complete denture CD
Secondary impression in complete denture CDNischala Chaulagain
 
Abutment selection in FPD
Abutment selection in FPDAbutment selection in FPD
Abutment selection in FPDDr. Anshul Sahu
 
Implant supported overdentures
Implant supported overdenturesImplant supported overdentures
Implant supported overdenturesMurtaza Kaderi
 

Tendances (20)

Overdenture
OverdentureOverdenture
Overdenture
 
Surveyor and technique of Surveying in Removable partial denture
Surveyor and technique of Surveying in Removable partial dentureSurveyor and technique of Surveying in Removable partial denture
Surveyor and technique of Surveying in Removable partial denture
 
Clinical and laboratory remoutning
Clinical and laboratory remoutningClinical and laboratory remoutning
Clinical and laboratory remoutning
 
Impression techniques in fpd
Impression techniques in fpdImpression techniques in fpd
Impression techniques in fpd
 
Tooth preparation for Metal ceramic crowns.
Tooth preparation for Metal ceramic crowns.Tooth preparation for Metal ceramic crowns.
Tooth preparation for Metal ceramic crowns.
 
Functionally Generated Pathway
Functionally Generated Pathway Functionally Generated Pathway
Functionally Generated Pathway
 
Occlusion in cd
Occlusion in cdOcclusion in cd
Occlusion in cd
 
CONNECTORS IN FPD.pptx
CONNECTORS IN FPD.pptxCONNECTORS IN FPD.pptx
CONNECTORS IN FPD.pptx
 
Provisional restoration
Provisional restorationProvisional restoration
Provisional restoration
 
Dentinogenic concept
Dentinogenic conceptDentinogenic concept
Dentinogenic concept
 
impression techniques of complete denture
impression techniques of complete dentureimpression techniques of complete denture
impression techniques of complete denture
 
RPI & RPA system
RPI & RPA systemRPI & RPA system
RPI & RPA system
 
Impression procedures for compromised ridges/cosmetic dentistry courses
Impression procedures for compromised ridges/cosmetic dentistry coursesImpression procedures for compromised ridges/cosmetic dentistry courses
Impression procedures for compromised ridges/cosmetic dentistry courses
 
Face bow
Face bowFace bow
Face bow
 
RPI system
RPI systemRPI system
RPI system
 
Impression - RPD
Impression - RPDImpression - RPD
Impression - RPD
 
Temporization in fixed prosthodontics
Temporization in fixed prosthodonticsTemporization in fixed prosthodontics
Temporization in fixed prosthodontics
 
Secondary impression in complete denture CD
Secondary impression in complete denture CDSecondary impression in complete denture CD
Secondary impression in complete denture CD
 
Abutment selection in FPD
Abutment selection in FPDAbutment selection in FPD
Abutment selection in FPD
 
Implant supported overdentures
Implant supported overdenturesImplant supported overdentures
Implant supported overdentures
 

Similaire à Impression for distal extension bases /certified fixed orthodontic courses by Indian dental academy

Impression Procedure for RPD’s- mandy.ppt
Impression Procedure for RPD’s- mandy.pptImpression Procedure for RPD’s- mandy.ppt
Impression Procedure for RPD’s- mandy.pptAmritaUpadhyay14
 
impression techniques in Removable Partial Denture
impression techniques in Removable Partial Denture impression techniques in Removable Partial Denture
impression techniques in Removable Partial Denture Dr.Richa Sahai
 
Jaw relatios in rpd / orthodontic straight wire technique
Jaw relatios in rpd   / orthodontic straight wire techniqueJaw relatios in rpd   / orthodontic straight wire technique
Jaw relatios in rpd / orthodontic straight wire techniqueIndian dental academy
 
Impression techniques in Removable partial denture.pptx
Impression techniques in Removable partial denture.pptxImpression techniques in Removable partial denture.pptx
Impression techniques in Removable partial denture.pptxDr vaishali shrivastava
 
Jaw relatios in rpd /prosthodontic courses
Jaw relatios in rpd   /prosthodontic coursesJaw relatios in rpd   /prosthodontic courses
Jaw relatios in rpd /prosthodontic coursesIndian dental academy
 
fdocuments.in_impression-materials-for-partial-denture.pptx
fdocuments.in_impression-materials-for-partial-denture.pptxfdocuments.in_impression-materials-for-partial-denture.pptx
fdocuments.in_impression-materials-for-partial-denture.pptxMohammedFouadAmeen
 
impression in RPD
impression in RPDimpression in RPD
impression in RPDitsdental
 
Impression anoop/prosthodontic courses
Impression anoop/prosthodontic coursesImpression anoop/prosthodontic courses
Impression anoop/prosthodontic coursesIndian dental academy
 
Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...
Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...
Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...Indian dental academy
 
Relining & rebasing/ Labial orthodontics
Relining & rebasing/ Labial orthodonticsRelining & rebasing/ Labial orthodontics
Relining & rebasing/ Labial orthodonticsIndian dental academy
 
Dipal reline n rebase
Dipal reline n rebaseDipal reline n rebase
Dipal reline n rebasedipalmawani91
 
Immediate dentures/ lingual orthodontics courses
Immediate dentures/ lingual orthodontics coursesImmediate dentures/ lingual orthodontics courses
Immediate dentures/ lingual orthodontics coursesIndian dental academy
 
Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy Indian dental academy
 
Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy Indian dental academy
 
Denture lining materials Malabar dental college & research centre
Denture lining materials Malabar dental college & research centreDenture lining materials Malabar dental college & research centre
Denture lining materials Malabar dental college & research centreDrAliyaAbdulla
 
Immediate dentures/ dental crown & bridge courses
Immediate dentures/ dental crown & bridge coursesImmediate dentures/ dental crown & bridge courses
Immediate dentures/ dental crown & bridge coursesIndian dental academy
 
Relining and rebasing in cd
Relining and rebasing in cdRelining and rebasing in cd
Relining and rebasing in cdirfanzunzani
 
Relining & rebasing / dental implant courses by Indian dental academy 
Relining & rebasing / dental implant courses by Indian dental academy Relining & rebasing / dental implant courses by Indian dental academy 
Relining & rebasing / dental implant courses by Indian dental academy Indian dental academy
 

Similaire à Impression for distal extension bases /certified fixed orthodontic courses by Indian dental academy (20)

spl imp tech.pptx
spl imp tech.pptxspl imp tech.pptx
spl imp tech.pptx
 
Impression Procedure for RPD’s- mandy.ppt
Impression Procedure for RPD’s- mandy.pptImpression Procedure for RPD’s- mandy.ppt
Impression Procedure for RPD’s- mandy.ppt
 
impression techniques in Removable Partial Denture
impression techniques in Removable Partial Denture impression techniques in Removable Partial Denture
impression techniques in Removable Partial Denture
 
altered-cast.pptx
altered-cast.pptxaltered-cast.pptx
altered-cast.pptx
 
Jaw relatios in rpd / orthodontic straight wire technique
Jaw relatios in rpd   / orthodontic straight wire techniqueJaw relatios in rpd   / orthodontic straight wire technique
Jaw relatios in rpd / orthodontic straight wire technique
 
Impression techniques in Removable partial denture.pptx
Impression techniques in Removable partial denture.pptxImpression techniques in Removable partial denture.pptx
Impression techniques in Removable partial denture.pptx
 
Jaw relatios in rpd /prosthodontic courses
Jaw relatios in rpd   /prosthodontic coursesJaw relatios in rpd   /prosthodontic courses
Jaw relatios in rpd /prosthodontic courses
 
fdocuments.in_impression-materials-for-partial-denture.pptx
fdocuments.in_impression-materials-for-partial-denture.pptxfdocuments.in_impression-materials-for-partial-denture.pptx
fdocuments.in_impression-materials-for-partial-denture.pptx
 
impression in RPD
impression in RPDimpression in RPD
impression in RPD
 
Impression anoop/prosthodontic courses
Impression anoop/prosthodontic coursesImpression anoop/prosthodontic courses
Impression anoop/prosthodontic courses
 
Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...
Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...
Sp.imp.procedures. /certified fixed orthodontic courses by Indian dental acad...
 
Relining & rebasing/ Labial orthodontics
Relining & rebasing/ Labial orthodonticsRelining & rebasing/ Labial orthodontics
Relining & rebasing/ Labial orthodontics
 
Dipal reline n rebase
Dipal reline n rebaseDipal reline n rebase
Dipal reline n rebase
 
Immediate dentures/ lingual orthodontics courses
Immediate dentures/ lingual orthodontics coursesImmediate dentures/ lingual orthodontics courses
Immediate dentures/ lingual orthodontics courses
 
Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy
 
Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy Rpd designing /certified fixed orthodontic courses by Indian dental academy
Rpd designing /certified fixed orthodontic courses by Indian dental academy
 
Denture lining materials Malabar dental college & research centre
Denture lining materials Malabar dental college & research centreDenture lining materials Malabar dental college & research centre
Denture lining materials Malabar dental college & research centre
 
Immediate dentures/ dental crown & bridge courses
Immediate dentures/ dental crown & bridge coursesImmediate dentures/ dental crown & bridge courses
Immediate dentures/ dental crown & bridge courses
 
Relining and rebasing in cd
Relining and rebasing in cdRelining and rebasing in cd
Relining and rebasing in cd
 
Relining & rebasing / dental implant courses by Indian dental academy 
Relining & rebasing / dental implant courses by Indian dental academy Relining & rebasing / dental implant courses by Indian dental academy 
Relining & rebasing / dental implant courses by Indian dental academy 
 

Plus de Indian dental academy

Indian Dentist - relocate to united kingdom
Indian Dentist - relocate to united kingdomIndian Dentist - relocate to united kingdom
Indian Dentist - relocate to united kingdomIndian dental academy
 
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...Indian dental academy
 
Invisalign -invisible aligners course in india
Invisalign -invisible aligners course in india Invisalign -invisible aligners course in india
Invisalign -invisible aligners course in india Indian dental academy
 
Invisible aligners for your orthodontics pratice
Invisible aligners for your orthodontics praticeInvisible aligners for your orthodontics pratice
Invisible aligners for your orthodontics praticeIndian dental academy
 
Development of muscles of mastication / dental implant courses
Development of muscles of mastication / dental implant coursesDevelopment of muscles of mastication / dental implant courses
Development of muscles of mastication / dental implant coursesIndian dental academy
 
Corticosteriods uses in dentistry/ oral surgery courses  
Corticosteriods uses in dentistry/ oral surgery courses  Corticosteriods uses in dentistry/ oral surgery courses  
Corticosteriods uses in dentistry/ oral surgery courses  Indian dental academy
 
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...Indian dental academy
 
Diagnosis and treatment planning in completely endntulous arches/dental courses
Diagnosis and treatment planning in completely endntulous arches/dental coursesDiagnosis and treatment planning in completely endntulous arches/dental courses
Diagnosis and treatment planning in completely endntulous arches/dental coursesIndian dental academy
 
Properties of Denture base materials /rotary endodontic courses
Properties of Denture base materials /rotary endodontic coursesProperties of Denture base materials /rotary endodontic courses
Properties of Denture base materials /rotary endodontic coursesIndian dental academy
 
Use of modified tooth forms in complete denture occlusion / dental implant...
Use of modified  tooth forms  in  complete denture occlusion / dental implant...Use of modified  tooth forms  in  complete denture occlusion / dental implant...
Use of modified tooth forms in complete denture occlusion / dental implant...Indian dental academy
 
Dental luting cements / oral surgery courses  
Dental   luting cements / oral surgery courses  Dental   luting cements / oral surgery courses  
Dental luting cements / oral surgery courses  Indian dental academy
 
Dental casting alloys/ oral surgery courses  
Dental casting alloys/ oral surgery courses  Dental casting alloys/ oral surgery courses  
Dental casting alloys/ oral surgery courses  Indian dental academy
 
Dental casting investment materials/endodontic courses
Dental casting investment materials/endodontic coursesDental casting investment materials/endodontic courses
Dental casting investment materials/endodontic coursesIndian dental academy
 
Dental casting waxes/ oral surgery courses  
Dental casting waxes/ oral surgery courses  Dental casting waxes/ oral surgery courses  
Dental casting waxes/ oral surgery courses  Indian dental academy
 
Dental ceramics/prosthodontic courses
Dental ceramics/prosthodontic coursesDental ceramics/prosthodontic courses
Dental ceramics/prosthodontic coursesIndian dental academy
 
Dental implant/ oral surgery courses  
Dental implant/ oral surgery courses  Dental implant/ oral surgery courses  
Dental implant/ oral surgery courses  Indian dental academy
 
Dental perspective/cosmetic dentistry courses
Dental perspective/cosmetic dentistry coursesDental perspective/cosmetic dentistry courses
Dental perspective/cosmetic dentistry coursesIndian dental academy
 
Dental tissues and their replacements/ oral surgery courses  
Dental tissues and their replacements/ oral surgery courses  Dental tissues and their replacements/ oral surgery courses  
Dental tissues and their replacements/ oral surgery courses  Indian dental academy
 

Plus de Indian dental academy (20)

Indian Dentist - relocate to united kingdom
Indian Dentist - relocate to united kingdomIndian Dentist - relocate to united kingdom
Indian Dentist - relocate to united kingdom
 
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...
1ST, 2ND AND 3RD ORDER BENDS IN STANDARD EDGEWISE APPLIANCE SYSTEM /Fixed ort...
 
Invisalign -invisible aligners course in india
Invisalign -invisible aligners course in india Invisalign -invisible aligners course in india
Invisalign -invisible aligners course in india
 
Invisible aligners for your orthodontics pratice
Invisible aligners for your orthodontics praticeInvisible aligners for your orthodontics pratice
Invisible aligners for your orthodontics pratice
 
online fixed orthodontics course
online fixed orthodontics courseonline fixed orthodontics course
online fixed orthodontics course
 
online orthodontics course
online orthodontics courseonline orthodontics course
online orthodontics course
 
Development of muscles of mastication / dental implant courses
Development of muscles of mastication / dental implant coursesDevelopment of muscles of mastication / dental implant courses
Development of muscles of mastication / dental implant courses
 
Corticosteriods uses in dentistry/ oral surgery courses  
Corticosteriods uses in dentistry/ oral surgery courses  Corticosteriods uses in dentistry/ oral surgery courses  
Corticosteriods uses in dentistry/ oral surgery courses  
 
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...
Cytotoxicity of silicone materials used in maxillofacial prosthesis / dental ...
 
Diagnosis and treatment planning in completely endntulous arches/dental courses
Diagnosis and treatment planning in completely endntulous arches/dental coursesDiagnosis and treatment planning in completely endntulous arches/dental courses
Diagnosis and treatment planning in completely endntulous arches/dental courses
 
Properties of Denture base materials /rotary endodontic courses
Properties of Denture base materials /rotary endodontic coursesProperties of Denture base materials /rotary endodontic courses
Properties of Denture base materials /rotary endodontic courses
 
Use of modified tooth forms in complete denture occlusion / dental implant...
Use of modified  tooth forms  in  complete denture occlusion / dental implant...Use of modified  tooth forms  in  complete denture occlusion / dental implant...
Use of modified tooth forms in complete denture occlusion / dental implant...
 
Dental luting cements / oral surgery courses  
Dental   luting cements / oral surgery courses  Dental   luting cements / oral surgery courses  
Dental luting cements / oral surgery courses  
 
Dental casting alloys/ oral surgery courses  
Dental casting alloys/ oral surgery courses  Dental casting alloys/ oral surgery courses  
Dental casting alloys/ oral surgery courses  
 
Dental casting investment materials/endodontic courses
Dental casting investment materials/endodontic coursesDental casting investment materials/endodontic courses
Dental casting investment materials/endodontic courses
 
Dental casting waxes/ oral surgery courses  
Dental casting waxes/ oral surgery courses  Dental casting waxes/ oral surgery courses  
Dental casting waxes/ oral surgery courses  
 
Dental ceramics/prosthodontic courses
Dental ceramics/prosthodontic coursesDental ceramics/prosthodontic courses
Dental ceramics/prosthodontic courses
 
Dental implant/ oral surgery courses  
Dental implant/ oral surgery courses  Dental implant/ oral surgery courses  
Dental implant/ oral surgery courses  
 
Dental perspective/cosmetic dentistry courses
Dental perspective/cosmetic dentistry coursesDental perspective/cosmetic dentistry courses
Dental perspective/cosmetic dentistry courses
 
Dental tissues and their replacements/ oral surgery courses  
Dental tissues and their replacements/ oral surgery courses  Dental tissues and their replacements/ oral surgery courses  
Dental tissues and their replacements/ oral surgery courses  
 

Dernier

The Singapore Teaching Practice document
The Singapore Teaching Practice documentThe Singapore Teaching Practice document
The Singapore Teaching Practice documentXsasf Sfdfasd
 
Patterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxPatterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxMYDA ANGELICA SUAN
 
CAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxCAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxSaurabhParmar42
 
The Stolen Bacillus by Herbert George Wells
The Stolen Bacillus by Herbert George WellsThe Stolen Bacillus by Herbert George Wells
The Stolen Bacillus by Herbert George WellsEugene Lysak
 
Education and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxEducation and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxraviapr7
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxraviapr7
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.raviapr7
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17Celine George
 
How to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 SalesHow to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 SalesCeline George
 
How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17Celine George
 
Practical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptxPractical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptxKatherine Villaluna
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfTechSoup
 
Benefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationBenefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationMJDuyan
 
General views of Histopathology and step
General views of Histopathology and stepGeneral views of Histopathology and step
General views of Histopathology and stepobaje godwin sunday
 
How to Add a many2many Relational Field in Odoo 17
How to Add a many2many Relational Field in Odoo 17How to Add a many2many Relational Field in Odoo 17
How to Add a many2many Relational Field in Odoo 17Celine George
 
Ultra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxUltra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxDr. Asif Anas
 
How to Show Error_Warning Messages in Odoo 17
How to Show Error_Warning Messages in Odoo 17How to Show Error_Warning Messages in Odoo 17
How to Show Error_Warning Messages in Odoo 17Celine George
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICESayali Powar
 
How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17Celine George
 

Dernier (20)

The Singapore Teaching Practice document
The Singapore Teaching Practice documentThe Singapore Teaching Practice document
The Singapore Teaching Practice document
 
Patterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptxPatterns of Written Texts Across Disciplines.pptx
Patterns of Written Texts Across Disciplines.pptx
 
CAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptxCAULIFLOWER BREEDING 1 Parmar pptx
CAULIFLOWER BREEDING 1 Parmar pptx
 
The Stolen Bacillus by Herbert George Wells
The Stolen Bacillus by Herbert George WellsThe Stolen Bacillus by Herbert George Wells
The Stolen Bacillus by Herbert George Wells
 
Education and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptxEducation and training program in the hospital APR.pptx
Education and training program in the hospital APR.pptx
 
Prescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptxPrescribed medication order and communication skills.pptx
Prescribed medication order and communication skills.pptx
 
Personal Resilience in Project Management 2 - TV Edit 1a.pdf
Personal Resilience in Project Management 2 - TV Edit 1a.pdfPersonal Resilience in Project Management 2 - TV Edit 1a.pdf
Personal Resilience in Project Management 2 - TV Edit 1a.pdf
 
Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.Drug Information Services- DIC and Sources.
Drug Information Services- DIC and Sources.
 
How to Solve Singleton Error in the Odoo 17
How to Solve Singleton Error in the  Odoo 17How to Solve Singleton Error in the  Odoo 17
How to Solve Singleton Error in the Odoo 17
 
How to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 SalesHow to Manage Cross-Selling in Odoo 17 Sales
How to Manage Cross-Selling in Odoo 17 Sales
 
How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17How to Add a New Field in Existing Kanban View in Odoo 17
How to Add a New Field in Existing Kanban View in Odoo 17
 
Practical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptxPractical Research 1 Lesson 9 Scope and delimitation.pptx
Practical Research 1 Lesson 9 Scope and delimitation.pptx
 
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdfMaximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
Maximizing Impact_ Nonprofit Website Planning, Budgeting, and Design.pdf
 
Benefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive EducationBenefits & Challenges of Inclusive Education
Benefits & Challenges of Inclusive Education
 
General views of Histopathology and step
General views of Histopathology and stepGeneral views of Histopathology and step
General views of Histopathology and step
 
How to Add a many2many Relational Field in Odoo 17
How to Add a many2many Relational Field in Odoo 17How to Add a many2many Relational Field in Odoo 17
How to Add a many2many Relational Field in Odoo 17
 
Ultra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptxUltra structure and life cycle of Plasmodium.pptx
Ultra structure and life cycle of Plasmodium.pptx
 
How to Show Error_Warning Messages in Odoo 17
How to Show Error_Warning Messages in Odoo 17How to Show Error_Warning Messages in Odoo 17
How to Show Error_Warning Messages in Odoo 17
 
Quality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICEQuality Assurance_GOOD LABORATORY PRACTICE
Quality Assurance_GOOD LABORATORY PRACTICE
 
How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17How to Use api.constrains ( ) in Odoo 17
How to Use api.constrains ( ) in Odoo 17
 

Impression for distal extension bases /certified fixed orthodontic courses by Indian dental academy

  • 1. IMPRESSION PROCEDURES FOR DISTAL EXTENSION BASES www.indiandentalacademy.com
  • 2. INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 3. Contents  INTRODUCTION  DEFINITIONS  RPD IMPRESSION Vs C D IMPRESSION  PRIMARY IMPRESSION  FINAL IMPRESSION METHODS  Mc LEAN’S TECHNIQUE  HINDEL’S TECHNIQUE  SELECTIVE PRESSURE TECHNIQUE  FUNCTIONAL RELINING TECHNIQUE  FLUID WAX TECHNIQUE  ALTERED CAST TECHNIQUE MODIFICATION  REVIEW OF LITERATURE  CONCLUSION  REFERENCES www.indiandentalacademy.com
  • 4. Definitions  Impression  A negative likeness or copy in reverse of the surface of an object ; imprint of teeth and adjacent structures for use in dentistry. GPT – 8 Partial denture impression  A negative likeness of a part or all of a partially edentulous arch - GPT – 8 www.indiandentalacademy.com
  • 5.  An impression of partially edentulous arch must record accurately the anatomic form of teeth and surrounding tissues.  Unless the cast upon which the prosthesis is to be constructed is an exact replica of mouth, the prosthesis can‘t be expected to fit properly and accurate cast can be obtained only from an accurate impression. www.indiandentalacademy.com
  • 6. Impression trays A receptacle in to which suitable impression material is placed to make negative likeness OR A device that is used to carry, confine and control impression material while making an impression. www.indiandentalacademy.com
  • 8. Impression trays can be classified broadly in to stock trays and custom trays Stock Trays Stock trays for partially edentulous patients may be perforated to retain the impression material or they may be constructed with a rimlock for this purpose. Another type of stock tray designed for the reversible type of hydrocolloid is water cooled trays. It contains tubes through which water can be circulated for purpose of cooling the tray. www.indiandentalacademy.com
  • 9. Disadvantages: STOCK TRAY a. The peripheral borders cannot be accurately recorded. b. Considerably more bulkier than a custom tray. www.indiandentalacademy.com
  • 10. Custom impression trays: a. Peripheral borders can be precisely recorded in the impression b. Thickness of impression material can be controlled. www.indiandentalacademy.com
  • 11. C. Well fitted tray will better support the impression in the palate, then avoiding even present danger of material slumping in vital areas. Custom trays are sometimes needed for mouths that are abnormally or of unusual configuration. www.indiandentalacademy.com
  • 12. Plaster Non-elastic Compound Impression Materials Waxes Impression Materials ZnO - Eugenol Aqueous Hydrocolloids Elastic Agar (reversible) Alginate (irreversible) Polysulfide Non-aqueous Elastomers Silicones Polyether www.indiandentalacademy.com Condensation Addition O’Brien Dental Materials & their Selection 1997
  • 13. RPD IMPRESSION Vs o COMPLETE DENTURE partial denture impression records relative soft yielding tissues (the oral mucosa) as well as a hard unyielding substance (the remaining teeth). IMPRESSION The complete denture impression records the edentulous mucosa with underlying bone only www.indiandentalacademy.com
  • 14. Removable partial denture impression need to record the teeth that are irregular in contour as well as varying in their vertical relations to occlusal plane. The chosen impression material must be capable of recording the tissue contours as accurately as possible without distortion, which occurs as impression is withdrawn. www.indiandentalacademy.com
  • 15. PRIMARY IMPRESSION Objective: To obtain an impression of all the standing teeth and denture - supporting tissues of each jaw from which study casts may be prepared. www.indiandentalacademy.com
  • 16. The purpose of the study casts are: To enable special trays and occlusion rims to be constructed if necessary. To examine the occlusion in detail on an articulator. By use of a surveyor, to plan the path of insertion of the proposed denture, arrive at a tentative design and plan any mouth preparation. www.indiandentalacademy.com
  • 18. Factors Influencing Support of Distal Extension Base Quality of Soft tissue covering edentulous ridge Type of bone making up denture-bearing area Design of partial denture Amount of tissue coverage of denture base Amount of occlusal forces Denture bearing area Fit of the denture base www.indiandentalacademy.com
  • 19. Impression Methods: There are basically two dual impression techniques.  The physiologic impression techniques that discussed are as follows:  Mc Lean’s and Hindel’s methods,  the functional relining method, and  the fluid wax method.  Selected pressure impression www.indiandentalacademy.com
  • 21.  The need for physiologic impressions was first recognized by McLean  For this dual impression a custom impression tray was constructed over a preliminary cast of the arch  A function impression of the distal extension ridge was made, and then hydrocolloid impression was made with the first impression held in its functional position with finger pressure www.indiandentalacademy.com
  • 23. o The greatest weakness of the technique was that finger pressure could not produce the same functional displacement of the tissue that biting force produced. o Many variations of this technique have been developed and advocated, but all require some form of finger loading pressure as the second impression is made. www.indiandentalacademy.com
  • 25. • Hindels and other developed irreversible hydrocolloid trays for the second impression that were provided with holes so that finger pressure could be applied through the tray as the hydrocolloid impression was made. www.indiandentalacademy.com
  • 27. o The main change that Hindels introduced to McLean ‘s original technique was that o The impression of the edentulous ridge was not made under pressure but was an anatomic impression of the ridge at rest made with a free flowing zinc oxide eugenol paste. www.indiandentalacademy.com
  • 28. o As the hydrocolloid second impression was being made, finger pressure was applied through the holes in the tray to the anatomic impression. o The pressure had to be maintained until the alginate was completely set. www.indiandentalacademy.com
  • 29. The main purpose of these techniques was to relate an impression of the edentulous ridge to the teeth under a form of functional loading. www.indiandentalacademy.com
  • 30. o A disadvantage of these techniques was that if the action of the retentive clasps of the partial denture is sufficient to maintain the denture base in relation to the soft tissues in the displaced or functional form, o Interruption of blood circulation would ensue, with possible adverse soft tissue reaction and resorption of the underlying bone. www.indiandentalacademy.com
  • 33. o Most methods of obtaining a physiologic impression for support of a distal extension denture base accomplish the impression procedure before completion of the denture, usually following the construction of the framework. o It is possible, however, to obtain the same results after the partial denture has been completed. o The technique is referred to as a functional reline. It consists of adding a new surface to the inner, or tissue, side of the denture base. www.indiandentalacademy.com
  • 34. o The procedure may be accomplished before the insertion of the partial denture, or it may be done at a later date because of bone resorption, the denture base no longer fits the ridge adequately. o Although the functional reline has many advantages, and for correcting the fit of denture base that has been worn for a period of time is essential, it does present many difficulties. www.indiandentalacademy.com
  • 35. o The main problems that arise are caused by failure to maintain the correct relationship between the framework and the abutment teeth during the impression procedure and failure to maintain accurate occlusal contact following the reline. www.indiandentalacademy.com
  • 36. o To allow room for the impression material between the denture base and the ridge, space must be provided. o One of the most accurate methods of ensuring uniform space for the impression is to adapt a soft metal spacer over the ridge on the cast before processing the denture base. o After processing, the metal is removed leaving an even space between the base and the edentulous ridge. www.indiandentalacademy.com
  • 38. The patient must maintain the mouth in a partially open position while the border molding and impression are being accomplished because: 1.The border tissues, cheek, and tongue are thus best controlled and 2.The relationship between the partial denture frame work and th teeth must be observed. www.indiandentalacademy.com
  • 41. The functional reline method has the advantage that the amount of soft tissue displacement can be controlled by the amount of relief given to the modeling plastic before the final impression is made. The greater the relief the less will be the tissue displacement. www.indiandentalacademy.com
  • 43. The fluid wax impression may be used to make a reline impression for an existing partial denture or to correct the distal extension edentulous ridge portion of the original master cast. www.indiandentalacademy.com
  • 44. OBJECTIVES To obtain maximum extension of the peripheral borders of the denture base while not interfering with the function of movable border tissues. To record the stress bearing areas of the ridges in their functional form. To record non pressure bearing areas in their anatomic form. www.indiandentalacademy.com
  • 45. The fluid wax impression is made with the open mouth technique so that there is less danger of over displacement of ridge tissue by occlusal or vertical forces. www.indiandentalacademy.com
  • 46. The term fluid wax is used to denote waxes that are firm at room temperature and have the ability to flow at mouth temperature. www.indiandentalacademy.com
  • 47. The most frequently used fluid waxes are Iowa wax, developed by Dr.Smith at the University of Iowa, and Korrecta Wax No. 4, developed by Dr. 0. C. Applegate and S. G Applegate at the Universities of Michigan and Detroit, respectively. Korrecta wax no. 4 is slightly more fluid than Iowa wax. www.indiandentalacademy.com
  • 48. The key to the use of fluid wax lies in two areas: space and time. Space refers to the amount of relief provided between the impression tray and the edentulous ridge. :1 to 2 mm is desired. Each time the tray is introduced into the mouth, it must remain in place 5 to 7 minutes to allow the wax to flow and to prevent buildup of pressure under the tray with resulting distortion or displacement of the tissue. www.indiandentalacademy.com
  • 49. o The clinical technique for the use of the fluid wax calls for the water bath maintained at 51° to 54° C into which a container of the wax is placed. o At this temperature the wax becomes fluid. The wax is painted on the tissue side of the impression tray with a brush. www.indiandentalacademy.com
  • 51. The borders must be short of all movable tissue, but not more than 2 mm short because the fluid wax does not have sufficient strength to support itself beyond that distance. www.indiandentalacademy.com
  • 52. Inaccuracies will develop if the wax is extended beyond that length. Originally a harder wax, Korrecta Wax no:1 was used to support the softer No.4 wax if extension beyond that length was needed. The no.1 wax however, is no longer available. www.indiandentalacademy.com
  • 53. o The wax is painted on the surface of the tray to a depth slightly greater than the amount of relief provided. The tray is seated in the mouth. o The patients must remain with the mouth approximately half open for about 5 minutes. o The tray is removed, and the wax examined for evidence of tissue contact. Where tissue contact is present the wax surface will be dull. www.indiandentalacademy.com
  • 54. o If needed additional wax is painted on those areas not in contact with the tissue. The tray must remain in the mouth a minimum of 5 minutes after each addition of wax. o The peripheral extensions are developed by tissue movements by the patient. o For the buccal and distobuccal extension in a mandibular impression the patient must move to a wide- open-mouth position. o This will activate the buccinator muscle and pterygomandibular raphe and produce the desired border anatomy. www.indiandentalacademy.com
  • 55. o For the proper lingual extension for a mandibular impression the patient must thrust the tongue into the cheek opposite the side of the arch being border molded. o The distolingual extension is obtained by having the patient press the tongue forward against the lingual surface of the anterior teeth. www.indiandentalacademy.com
  • 56. These movements must be repeated a number of times after the impression has been in the mouth long enough for the wax to have softened sufficiently to flow. www.indiandentalacademy.com
  • 57. o When the impression evidences complete tissue contact and when the anatomy of the limiting border structure is evident, the impression should be replaced in the mouth for 12 minutes. o This final time to be certain that the wax has completely flowed and released any pressure that may be present. www.indiandentalacademy.com
  • 59. The finished impression must be handled carefully and the new cast poured as soon as possible because the wax is fragile and subject to distortion. www.indiandentalacademy.com
  • 60. The fluid wax impression technique can produce an accurate impression if the technique is properly executed The procedure is time consuming, but if the time periods are not followed accurately, an impression with excessive tissue displacement will result. www.indiandentalacademy.com
  • 62. This impression technique attempts to direct more force to those portions of the ridge able to absorb the stress without adverse response Tissue surface of the tray is selectively relieved . www.indiandentalacademy.com
  • 63. Impression materials Zinc-oxide Eugenol paste Rubber base materials www.indiandentalacademy.com
  • 64. Impression technique Border molding Making impression with the ZOE or Rubber base materials The critical point is to determine visually that all rest and indirect retainers are completely seated www.indiandentalacademy.com
  • 68. Technique 1. Fashioning custom acrylic resin impression tray to retention lattice work of removable partial denture. 2. Developing denture base impression on these trays. 3. Removing edentulous ridge from master cast. 4. Securing framework with developed bases to master cast. 5. Pouring the impression with dental stone. www.indiandentalacademy.com
  • 70. www.indiandentalacademy.com Leader in continuing dental education www.indiandentalacademy.com