PRIMARY & SECONDARY IMPRESSION IN CD.ppt

PRIMARY & SECONDARY IMPRESSION IN CD

1. PRIMARY & SECONDARY IMPRESSION
IN COMPLETE DENTURE
1
DR SRINIVAS REDDY
MDS
Dept Of Prosthodontics
Navodaya Dental College

2. COMPLETE DENTURE
IMPRESSION :-
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a complete denture impression is
a negative registration of the
entire denture bearing,
stabilizing and border seal areas
present in the edentulous mouth.
(GPT-9)
PRELIMINARY IMPRESSION : -
a negative likeness made for the purpose of diagnosis,
treatment planning, and/or the fabrication of a custom
impression tray preload . (GPT-9)

3. IMPRESSION TRAYS:-
It is a device used to carry ,confine & control
impression material while making an impression.

4. BORDER MOLDING : -
the shaping of impression material along the
border areas of an impression tray by
functional or manual manipulation of the soft
tissue adjacent to the borders to duplicate the
contour and size of the vestibule (GPT-9)
4
•v

5. Maxillary stress bearing and relief
areas
primary
Hard palate
on either side
of raphae
Firm
tuberosity
Secondar
y
Rugaearea
Crest of
Residual
Alveolar Ridge
Relief
Incisive Foramen
Mid Palatine Raphae
Palatal Tori
Sharp Spiny Processes
5

6. Mandibular Stress bearing
&Reliefareas
Primary
Buccal ShelfArea
RetromolarPad
Secondary
slopes of
Residual Alveolar
Ridge
Relief
MandibularTori
MentalForamen
Genial Tubercles
Prominent RetromylohyoidRidge
6

7. Principles
of
Impression
Making
Support
Retention
Stability
Esthetics
Preservation
of alveolar
ridges
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8. (1)Diagnostic Impression :-
•The negative replica of the oral tissues used to
prepare a diagnostic cast.
•Used for study purposes like measuring the
undercuts, locating the path of insertion.
•Is made as a part of treatment plan and to estimate
the amount of pre-prosthetic surgery required.
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Depending on the purpose of theimpression

9. (2) Primary Impression:-
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•An impression made for the purpose of
construction of a
special tray.
•There should be at least 6mm clearance between
the stock tray and the ridge for materials used in
making primary impression.
(3)Secondary Impression: -
•Making the wash impression.
•Developing the posterior palatal seal.

10. Operator position for
maxillaryimpression
Correct
Incorrect
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11. Operator position for
MandibularImpression
Correct
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Incorrect

12. Making the preliminary
impression
Tray should be
adjusted by bending
Selection of stocktray Positionborders at
hammularnotches
Lift the tray anteriorly,
3-5 mm space for
impression material
1
2

13. Border of the tray
should be cut if
required
Borders should be
smoothened
Material
Manipulation
(hot water bath
at 140F)
1
3

14. Placing the tray in the patientsmouth.
Performing Movements to mold thematerial.
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4

15. •Impression compound is softened in a hot water bath at 140°F.
• After kneading it is loaded on to thetray and shaped
roughly to the shape of the ridge with the fingers.
•The distolingual flange areas can be molded with fingers to
simulate the final impression.
MandibularImpression
1
5

16. •The left posterior corner of the tray is inserted while retracting the
right cheek with operator’s left hand and tray is rotated and
centralized over the ridge.
1
6

17. •Patient is instructed to lift the tongue, and tray is seated while applying
pressure
•Light border molding movements are performed including tongue
movements.
•Compound is allowed to harden and chilled after removal impression is
inspected.
1
7

18. Border molding
(Peripheral
tracing , Muscle
trimming)
1
8
•Border molding materials
include:
•Modelling compound sticks
(GreenStick)
•Polyether impressionpaste
•Tissue conditioners
•Auto polymerizing acrylic
resin
•Impression waxes

19. Methods of border
moulding
Labial and
Buccal
borders
Smiling
whistling
grinning
(1) Functional method :-
Normal functional movements mold the borders
in harmony with muscle action
Buccal frenum
and Buccal
borders
Sucking
Lingual
borders
Licking the lips
and tongue
movements
Lingual border
and Floor of
mouth
Swallowing
Distobuccal
borders
Opening, closing
and side to side
movements
1
9

20. (2)Digital manipulation :-
•Dentist manipulates the lips and cheeks of
the patient to simulate the influence of
these on the denture borders.
•Easy ; does not require much of patient
cooperation.
•Influenced by the direction of movement
and the force applied.
(3)Combined :-
•Border molding is usually done by a
combination of digital manipulation by the
dentist and functional movements by the
patients.
2
0

21. Steps in Sectional
bordermolding
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Softened compound added alongdry
borders of required segment
Cheek outward, downward and
inward
Softened again with alcoholtorch.
Tempered in warm waterbath.

22. Labial BorderMolding
outward, downward andinwards
Molding theFrenum
Compoundplacedonposteriorborder.Tray seated in mouth with firmpress6u6 re.

23. Compound placed on posteriorborder
71Compound added on buccalborder
The tray gently seated inplace.
The borders should besmooth,round
andsymmetrical

24. Compound placed on labialborder Labial BorderMolding
outward, upward andinward
Lingual Border MoldingMovements
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25. 7
7

26. Secondaryimpression
The final impression material is mixed according to
manufacturer’s directions and uniformly distributed within the
tray.
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27. 7
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28. CONCLUSION
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•The main objective of impression making is to
fabricate dentures having maximum retention and
stability without causing any damage to the
supporting structures. Thus the choice of
impression technique and material is made by the
dentist on the basis of the oral conditions,
concepts of function of the tissues surrounding the
denture and ability to handle the available
impression material.