CLINICAL STEPS FOR COMPLETE DENTURE
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EXAMINATION,DIAGNOSIS & TREATMENT PLANING.
PREPROSTHETIC SURGERY ( IF REQUIRE)
PRIMARY IMPRESSION
SECONDARY IMPRESSION
JAW RELATION RECORD
TRY-IN PROCEDURE
DENTURE INSERTION
POST INSERTION FOLLOW-UP
CONTENTS
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INTRODUCTION
PRINCIPLES OF IMPRESSION MAKING
OBJECTIVES OF IMPRESSION MAKING
CLASSIFICATION OF IMPRESSION TECHNIQUES
STEPS IN IMPRESSION MAKING
PRIMARY IMPRESSION MAKING
INTRODUCTION
• The beginning of a good denture starts with making of a good
impression,so a good impression is a stepping stone
Definition
A complete denture impression is a negative registration of
the entire denture bearing, stabilizing and border seal
areas present in the edentulous mouth ( GPT-7)
Principles of making an impression:
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Tissues of the mouth must be healthy.
Impression should include all of the basal seat within the limits of the
health and function of the supporting and limiting tissues.
The borders must be in harmony with the anatomical and
physiological limitations of the oral structures.
Selective pressure should be placed on the basal seat during the
making of the impression
Proper space for the selected impression material should be provided
within the tray
Impression must be removed from the mouth without damage to the
mucous membranes of the residual ridges.
Guiding mechanism should be provided for correct positioning of the
imp. tray.
Tray and impression material should be made of dimensionally stable
materials.
External shape of the material should be similar to the complete
denture
OBJECTIVES OF IMPRESSION MAKING
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Support
Retention
Stability
Esthetics
Preservation of Alveolar Ridges
SUPPORT
It is the foundation area on which a dental
prosthesis rests.
GPT-8
Dental support is the resistance to vertical
forces of mastication and to occlusal or
other forces in a direction towards the
basal seat.
The mucoperiosteum along with the alveolar
ridges is not meant to receive functional
loads.
It is thus necessary, to enhance the available
support by utilizing maximum coverage of all
usable ridge bearing areas.
Areas of support:
The areas of support are divided into:
• PRIMARY
• SECONDARY
• SLIGHT
PRIMARY:
These are the areas of the edentulous ridge that are at
right angles to occlusal forces and usually do not resorb
easily.
MAXILLARY:
Posterior ridges and flat areas of the palate.
MANDIBULAR:
Buccal shelf area and posterior ridges.
SECONDARY:
Areas of the edentulous ridge that are greater
than at right angles to occlusal forces or are
parallel to them; also the areas of the
edentulous ridge that are at right angles to
occlusal forces but tend to resorb under load.
MAXILLARY:
Anterior alveolar ridge and rugae area.
MANDIBULAR:
Anterior alveolar ridge and posterior ridge crest.
SLIGHT:
Areas of very displacable tissues, that is ; all the
vestibular areas that provide very little
support but are needed for the very important
peripheral seal.
Importance of buccal shelf area:
 It is the area of bone between the extraction sites
of molars and the external oblique ridge.
 It has an intact cortical plate and tends not to
resorb under load.
 The buccinator muscle in this region has its fibres
in a horizontal direction which is relatively
inactive and flaccid during function
Importance of covering the pear
shaped pad:
 Craddock coined the term pear shaped
pad and refers to the area formed by
residual scar of the third molar and the
retromolar papilla.
 Sicher has described retromolar pad as a
soft elevation of mucosa that lies distal to
the third molar.
The mucosa of the pear shaped pad is
usually attached gingiva. An examination
after drying will reveal that the mucosa is
firm, stippled and has a dull appearance.
The retromolar pad has a shiny and soft
appearance.
The pad can be also used for determining
the occlusal plane of the lower denture.
Palatal support:
The palate requires relief only when there is a
presence of torus or the area over the midpalatine raphae is thin.
In most of the cases horizontal part of the hard
palate can be used for gaining support.
Methods to improve support are
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Surgical removal of pendulous tissue
Use of tissue conditioning materials
Surgical removal of sharp or spiny
mandibular ridges
Surgical enlargement of ridge
Implants
RETENTION
It is the resistance to removal in a direction opposite
to that of insertion
The factors of retention are :
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Adhesion
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Cohesion
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Interfacial surface tension
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Capillarity
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Mechanical locking into undercuts
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Peripheral seal and atmospheric pressure
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Oral and facial musculature
ADHESION
• The physical attraction of unlike molecules to
one another.
• Role of saliva
• The amount of adhesion present is
proportional to denture base area.
COHESION
• The physical attraction of like molecules for
each other.
• Watery serous saliva can form a thinner film
and is more cohesive than thick mucous
saliva.
INTERFACIAL SURFACE TENSION
• The tension or resistance to separation
possessed by the film of liquid between two
well adapted surfaces.
• Saliva should be thin and even.
• Perfect adaptation between tissues and
denture base.
• Cover large area
• Good adhesive and cohesive forces.
CAPILLARY ATTRACTION
• That quality or state, because of surface
tension causes elevation or depression of the
surface of a liquid that is in contact with a
solid.
• Closeness of adaptation.
• Greater surface of denture bearing area.
• Thin film of saliva.
ATMOSPHERIC PRESSURE &
PERIPHRAL SEAL
• Peripheral seal is area of contact between
peripheral borders of denture and resilient
limiting structures.
• Prevents air entry between denture surface
and soft tissue.
• Retention by atmospheric pressure is directly
proportional to denture base area.
• UNDERCUTS: Unilateral undercuts aid in
retention.
• ORAL MUSCULATURE: Supplementary
retentive forces.
• Forces from buccal musculature and tongue
are neutralized- neutral zone.
• Artificial teeth arranged in neutral zone to
achieve good retention.
STABILITY :
Stability of a denture is its ability to remain securely in
place when it is subjected to horizontal
movements.
For the denture to be stable it requires
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Good retention
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Non interfering occlusion
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Proper tooth arrangement
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Proper form and contour of the polished surfaces
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Proper orientation of the occlusal plane
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Good control and co ordination of the patients
musculature.
ESTHETICS
• The role of esthetics in impression making
refers to the development of the labial and
buccal borders so that they are not only
retentive but also support the lips and cheeks
properly
PRESERVATION OF ALVEOLAR RIDGES
M.M.DE VAN DICTUM
THE PRESERVATION OF THAT WHICH IS OF UTMOST
IMPORTANCE AND NOT THE METICULOUS REPLACEMENT
OF THAT WHICH HAS BEEN LOST .
IMPRESSIONS SHOULD RECORD THE DETAILS OF THE
BASAL SEAT AND PERIPHERAL STRUCTURES IN AN
APPROPRIATE FORM TO PREVENT INJURY TO THE ORAL
TISSUES.
THE PERIPHERAL TISSUES SHOULD BE RECORDED
ACCURATELY TO PREVENT OVER-EXTENSION OF THE
DENTURE AND TISSUE IRRITATION.
Impression techniques may be
classified depending on:
a) Amount of pressure used
1. Pressure technique( MUCOCOMPRESSIVE)
2. Minimal pressure technique( MUCOSTATIC)
3. Selective pressure technique
b) Based on the position of the mouth while making
impression
1. Open mouth
2. Close mouth
c) Based on the method of manipulation for border
molding.
1. Hand manipulation
2. Functional movements
Pressure theory or mucocompressive theory:
This theory was proposed on the assumption that tissues recorded
under functional pressure provided better support and retention for
the denture
STEPSPrimary impression made with impression compound
Special tray made
Impression made with compound
Bite rim made with compound
Relief of mid palatine raphae
Peripheral muscle trimming
Borders are molded by asking the patient to perform functional
movements.
Minimal pressure or mucostatic theory –
The main advantage of this technique is its high regard for tissue health & preservation.
STEPS• A compound impression is made.
• A baseplate wax space is adapted.
• A special tray is made.
• Spacer is removed and an impression is made with a free
flowing material with little pressure.
• Escape holes are made for relief.
Selective pressure theory
• Advocated by Boucher in 1950 it combines the principles of both
pressure and minimal pressure technique.
• In this technique idea of tissue preservation is combined with
mechanical factor of achieving retention, through minimum pressure
which is within physiologic limits of tissue tolerance.
STEPS IN MAKING AN IMPRESSION( PRIMARY)
Preliminary examination of the patient
Seating the patient
Selection of the tray
Selection of the material
Making impression
SEATING OF THE PATEINT
Position of the operator for
maxillary impression
( 11 O’ CLOCK)
Position of the operator for
mandibular impression
(7 O’ CLOCK)
Types of Trays
TRAYS DESIGN
SECTIONAL
STOCK
EDENTULOUS
PERFORATED
TRIPLE
DENTULOUS
CUSTOM
EDENTULOUS
DENTULOUS
NONPERFORATED
TRAY MATERIALS
PLASTIC
RESIN
HEAT CURE RESIN
SHELLAC BASE PLATE
SELF CURE RESIN
METALLIC
STOCK TRAYS
PERFORATED TRAYS
NON PERFORATED TRAYS
CUSTOM TRAY