impression

Impression'sImpression's

30-10-07

DEPARTME T OF PROSTHETICS @ Chettinad Hospital & Research Institute

Pre-Prosthetic lectureDr. Vinamra Dhariwal

Types of Impression in

Prosthodontics

• Complete Denture Impressions

• Partial denture Impressions

RPD

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Pre-Prosthetic lecture

RPD

FPD

• Implants

• Maxillo Facial Prosthesis

Dr. Vinamra Dhariwal

STEPS IN DENTURE MAKING-CLINICAL

� EXAMINATION AND CASE SHEET

� PRIMARY IMPRESSION

� SECONDARY IMPRESSION

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� JAW RELATION

� WAX TRIAL

� DENTURE INSERTION

� REVIEW


STEPS IN DENTURE

MAKING- (LAB )

� PRIMARY CAST FABRICATION AND

SPECIAL TRAY FABRICATION

� SECONDARY or MASTER CAST FABRICATION

� DENTURE BASE & OCCLUSAL RIM FABRICATION

K

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� DENTURE BASE & OCCLUSAL RIM FABRICATION

� ARTICULATION AND TEETH SETTING

� WAX UP AND PROCESSING

� REVIEW AND OCCLUSAL ADJUSTMENT


STEPS IN DENTURE MAKING-

� EXAMINATION AND CASE SHEET

� PRIMARY IMPRESSION

� PRIMARY CAST FABRICATIO A D

SPECIAL TRAY FABRICATIO

� SECO DARY or MASTER CAST FABRICATIO

CLINICAL LABORATORY

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� JAW RELATION

� WAX TRIAL

� DENTURE INSERTION

� REVIEW

� DE TURE BASE & OCCLUSAL RIM FABRICATIO

� ARTICULATIO A D TEETH SETTI G

� WAX UP A D PROCESSI G

� REVIEW A D OCCLUSAL ADJUSTME T


IMPRESSION

• An impression is a negative registration of dental

and associated structures.

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• A complete denture impression is negative

registration of the entire denture bearing,

stabilizing, and border seal areas present in the

edentulous mouth


Impression

• Definition: It is the negative replica of the

denture bearing ,border sealing and the

stabilizing areas which is recorded with the

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stabilizing areas which is recorded with the

help of a semi solid or a plastic material

which becomes relatively hard or set when

in contact with the oral tissues.


PRIMARY IMPRESSION

• Definition: An impression made for the purpose of diagnosis or construction of a tray.

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• PRIMARY CAST : A positive reproduction of the upper or lower jaw tissues that is made with an impression and over which coustom/special trays may be fabricated.


Making of impression

• To evaluate the anatomical structures and

limits in the oral cavity with our eyes and

fingers, then to shape and mold the

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fingers, then to shape and mold the

impression material in to a negative likeness

of those structures.


Requirements of Good Impression

It is very important to gain the following requirements for mastering the art of impression making:

�Knowledge of the oral anatomy

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�Knowledge of the oral anatomy

�Knowledge of a reliable technique

�Understanding of materials

�Skill

�Patient management


Types of Impression

• Impression may be :

A) to obtain study cast

B) to obtain primary cast

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B) to obtain primary cast

C) to obtain final or working cast

D) to be used as an index


Armamentarium

• Impression trays

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• Impression Material


IMPRESSION TRAYS

Definition : A receptacle or device used to

used to carry the impression material to the

mouth, confine the material in apposition to

the surfaces to be recorded , and control the

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the surfaces to be recorded , and control the

impression material while it sets to form the

impression.


IMPRESSION TRAYS

Requirements :

1) Rigid but not thick

2) Retain shape

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3) Accommodate material in

uniform thickness

4) Easy to trim or adjust

5) Smooth without sharp edges


Impression Trays

• Stock Trays

Perforated Trays

Non Perforated Trays

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Non Perforated Trays

Water cooled trays

Rim lock Trays

• Special Trays / Custom made Tray


Trays Classification

• Dentulous Trays

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• Edentulous Trays


Edentulous Trays- perforated

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Edentulous Trays-perforated

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RIM LOCKED TRAYS

-perforated

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Edentulous Trays-

non-perforated

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Dentulous Trays

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Dentulous Trays-

Rim locked

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WATER COOLED TRAYS

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Impression Materials

• Inelastic / Rigid

• Elastic

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• Reversible

• Irreversible

• Thermoplastic

• Thermoset


Complete Denture Impressions

• Muco Static

• Muco Compressive

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• Muco Compressive

• Selective Pressure


Impression Techniques

• Open Mouth

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• Closed Mouth


BASIC PRINCIPLES OF

IMPRESSION MAKING

1) PRESERVATION OF ALVEOLAR RIDGE

2) SUPPORT

3) RETENTION

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3) RETENTION

4) STABILITY

5) ESTHETICS


Types of Impression

• Impression for

A) Edentulous

B) Dentulous

30-10-07DEPARTME T OF PROSTHETICS @ Chettinad Hospital & Research Institute


B) Dentulous

C) Partially Edentulous

D) Maxillo-Facial

E) Implant


Impressions for Complete

Denture

• Primary Impression

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• Secondary Impression


impression

Documents

art of impression

coustomspecial trays

cast d

perforated trays water

primary cast c

entire denture bearing

lab primary cast fabrication

plastic material