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1. Techniques and methods of making
impressions in edentulous patients

2. Complete dentures
 Keeping the complete denture on the base depends
mainly on the correct impression taking in the oral
cavity.

3. Definition
 An impression is a negative tissue shape
made of an impression material placed in
the oral cavity in a plastic state and taken
out after setting in a rigid or elastic state.
 It is a negative of the prosthetic field on
which the complete prosthesis will be
based.

4. Topographic elements of the
toothless maxilla and mandible

6. Types of impressions
 Due to the purpose of the impression, we distinguish:
 a. Orientation impressions - are made in order to obtain
approximate models, used for diagnostics, establishing a
treatment plan and for making individual trays.
 They are made on standard buckets.
 b. Working impressions - are made in order to obtain
working models, used to make dentures.
 Models for complete dentures are made with individual
spoons.

7. Types of impressions
 Due to the activity of the muscles of the lips, cheeks
and tongue, we distinguish:
 a. Anatomical impressions
 b. Functional impressions

8. Types of impressions
 Anatomical impressions:
 • reproduce the shape of the anatomical elements of
the oral cavity without taking into account the
muscular activity
 • are taken on standard impression trays (the
impression depends on the size and shape of a
standard tray, no exact adjustment to the range of the
prosthetic field, usually they significantly exceed the
neutral zone, no rim shape)
 • for full dentures they are taken with alginate masses,
elastomers (formerly with impression gypsum)

10. Types of impressions
 Functional impressions:
 • are collected during the patient's movements of the
jaw, tongue, lips and cheeks.
 • changing the position of movable soft tissues,
muscle attachments and ligaments (functional
movements) shapes the edges of the impression (the
impression shows the shape, thickness of the rim and
the reach of the future prosthesis)
 • are collected using individual spoons
 • we distinguish functional impressions:
 active - movements performed by the patient
 passive - movements performed by a doctor

12. Types of impressions
 Due to the number of layers of the mass, there are
impressions:
 a. single-layer,
 b. two-layer,
 c. multi-layered (at the edge of the prosthetic field 2
layers of impression materials, one layer of the
material over the entire prosthetic field)

13. Types of impressions
 Impressions made to modify or repair dentures:
a. relining (made on the denture for relining, rebasing))
b. complementary (repair of dentures - adding a clamp
or tooth or extending the range of the plate)

14. Anatomical impressions
On standard trays
On their basis, a plaster model is cast in the laboratory.
Depending on the purpose, called a model:
preliminary, diagnostic, and orientation
With toothlessness, it is used to make an individual spoon.

15. Alginate impression
 Tray covered with adhesive tape or perforated
 Kromopan mass, Hydrogum
 When taking an impression, shape the mass during the
active work of mimic muscles and tongue movements

16. The most common causes of
errors in taking anatomical
impressions are:
 wrong selection of a standard bucket (size, type)
 the wrong amount of impression material on the tray
 bad force exerted on the spoon by the doctor during its
collection
 the impression material detaches from the tray when
removing the impression from the oral cavity
 the lack of cleanliness of the prosthetic field (remains of
denture adhesive, food remains, mucus)
 wrong placement of the impression material on the tray
(important anatomical structures not covered)
 pushing the impression material through the lips and tongue
(the mass does not drip into the lingual pockets)

17. The most common causes of
errors in taking anatomical
impressions are:
 mass too thick or too thin
 poorly mixed mass (visible powder)
 leaving air bubbles
 puncture the spoon through the impression
 strong gag reflexes distorting the binding impression
 too quick removal from the mouth (before the mass is
completely set)

21. Functional impressions
 Individual tray:
 • it is used to make a functional impression after adjusting
it to the conditions of the patient's oral cavity
 • can be made of acrylic, shellac, light-curing materials,
thermoplastics shaped by hand or in erkopress devices
 • consists of a base plate and a handle
 - the basal plate must not exceed the mobility limit of the
mucosa,
 - the handle should be in the geometric center of the
spoon (center of the palate - jaw) and in the area
of ​​premolars (mandible) and its shape should not obstruct
functional movements

22. Individual tray for mandible

23. Individual tray for maxilla

25. Incorrect individual tray

26. Individual impression trays
 with handles (in the technique of pressure-free impressions, with
the mouth open)
 trays with occlusal wax shafts (in the technique of occlusal
impressions, with the mouth closed)
 the reach of the tray is scratched each time by the doctor on a
plaster model or, less frequently, on an anatomical impression
 adjustment of individual tray in the mouth according to Herbst
tests
 it is an accurate estimate of the bucket range in relation to
- mobile mucosa,
- Floor of the mouth and tongue,
- muscle attachments and frenulum
 begins with the patient's mouth half open, and then the individual
tests are performed

30. Herbst Tests for the maxilla
• Place of shortening the range
• bilaterally from the maxilla tumor
to the area of ​​the second molar
• vestibularly in the area of ​​the
front teeth from canine to canine
• bilateral vestibularly from the
second molar to the first
premolar
• Test numer
• I mouth wide opening
• II whistle lips position
• III mimic movements,
wide smile

31. Notes and errors
Test I – tray drop may be caused by:
 a tight pterygoid fold
 spoon too long covering the front part of the soft
palate and exceeding the aponeurosis attachment
Test II - the tray drop may be caused by the tightening of
small incisal folds

32. Herbst Tests for mandible
Numer testu Miejsce skrócenia zasięgu łyżki
I - szerokie otwarcie ust
obustronnie przedsionkowo od trójkątów
pozatrzonowcowych do okolicy pierwszych trzonowców
II - oblizywanie wargi górnej i
dolnej
obustronnie językowo od trójkątów pozatrzonowcowych do
okolicy pierwszych trzonowców
III - dotykanie końcem języka
błony śluzowej policzków
obustronnie językowo przy przeciwległej stronie w miejscach
odległych o 1 cm od przyczepu wędzidełka języka w obrębie
od kła drugiego przedtrzonowca
IV - wysuwanie języka ponad
górną wargę
okolice wędzidełka języka w obrębie siekaczy przyśrodkowych
V - ułożenie warg jak przy
gwizdaniu
przedsionkowo od kła do kła

33. Notes and errors
 Test I - the lifting of the tray may be caused by a
tightening of the palato-lingual folds or sway-
mandibular folds
 Test II - the tray should be carefully adjusted because
it can be used to stabilize the prosthesis in difficult
conditions - Supple II and III - posterolateral recess of
the oral cavity (Bowen)
 Test III and IV - you can correct the tray when the
doctor holds it with his fingers or correct this area
already in the finished prosthesis
 Test V - tray lift may be caused by additional folds in
the premolars area

34. Impression tray seal
 After adjusting the individual upper tray, we seal (trays)
in the rear section on the A - H line by applying a layer
of wax along the entire length of the rear edge
 Test to verify proper sealing (finger balancing test on
tray handle)
 PURPOSE - checking the correct range of the posterior
border of the future prosthesis

37. Fuctional impressions
 Types of functional impressions:
1. due to the extent of the prosthetic field
 a. mucostatic
 b. mucodynamic (extensional)

38. Functional impressions
 Mucostatic
recreate the shape of a prosthetic field covered with an
immobile mucosa
the border of the impression runs along the border of
mucosal mobility (along the neutral zone)
mainly used in the jaw
collected with masses with specified setting time
(impression pastes, elastomers)

39. Functional impressions
 Mucodynamic (extensive dentures)
reproduce the shape of the anatomical elements of the oral cavity
covered with both immobile and mobile mucosa
mainly used in the mandible with significant loss of the prosthetic
base
they give the possibility of extending the impression in the area
of ​​the front tongue pocket, cheek pocket, and the area of ​​the circular
muscle of the mouth
 There are 2 methods of taking impressions:
the use of a material with an indefinite setting time, i.e. the classic
Herbst method with the use of Adheseal impression wax (allows you
to constantly make corrections, add material in areas favorable for
widening)
widening the individual tray with dense elastomers (putty, e.g.
Xantopren Function) or impression waxes, and then taking a functional
impression with a thinner consistency.

40. Functional impressions
 Types of functional impressions:
2. due to the pressure exerted on the tissues
a. pressure-free - masses of medium or low elasticity
b. compression - masses of high elasticity
c. selective-relieving, e.g. impression according to
Kozłowski

41. Selectively relieving impression according
to Kozłowski
Aim - to relieve the places that could be excessively pressed
by the prosthesis (palatal shaft, incisive papilla, larger palatal
openings)
zinc oxide-eugenol paste (high resilience, possibility of
combining layers)
stages:
 mark the places of relief on the anatomical model and
cover them with a thin layer of thin wax,
 we make an individual spoon, take a functional
impression,
 mark the places of relief on the mucosa and re-insert the
impression into the mouth to mark the marked places on
the impression

42.  remove the impression material in places of relieving
and perforate the spoon,
 put the impression paste on the prepared impression
and press it firmly to the base, thanks to the
perforations there is no pressure on these areas
 the working model obtained from the selectively
relieving impression does not require further relieving

43. Functional impressions
 Types of functional impressions:
3. Due to the source of pressure, we distinguish
pressure impressions
a. physiological - pressure exerted by the patient's
muscles through occlusal shafts or artificial teeth
b. non-physiological - pressure exerted by the doctor's
hands

44. Functional impressions
 Types of functional impressions:
4. impressions can be taken
a. with open mouth (classic method)
b. with closed mouth (Marxkors method, Płonka
method)

45. Functional impressions
 Types of functional impressions:
5. due to the way of taking the impression
a. passive (movements are made by a doctor, elderly
patient or poorly cooperating patient)
b. active (movements performed by the patient - the
classic Herbst method)

46. Classic Method
1. Materials:
a. zinc oxide-eugenol pastes, e.g. Neogenate, Ash Impression

47. Classic Method
2. Stages:
a.adjustment of the individual bucket
b. rinsing the mouth thoroughly with water
c. to familiarize the patient with the movements involved in adjusting
the trays before applying the impression material (Herbst tests)
d. functional shaping of the edges of the spoon (with mucodynamic
impression)
e. preparing the impression material and applying it in an even, thin
layer on the tray
f. inserting the spoon with the mass into the oral cavity and placing it
carefully and pressing it against the ground
g. shaping the periphery of the impression according to Herbst's tests
while setting the mass
h. after setting the mass, remove the spoon and check the quality of
the impression

51. Classic method Primary sealing of
the impression
 After taking the upper functional impression, you can
perform the primary sealing of the posterior border of
the impression on the AH line, by applying a layer of
the same impression material or a mass with greater
resilience to the posterior border of the impression
and reintroducing the impression into the oral cavity.
 Not to be confused with the Custom Bucket Packing

52. Impression by the Marxkors method with
the mouth closed (bite impression)
 the pressure exerted on the mass should be regulated by the strength of
the patient's muscles and not by the doctor's hand
 the impression is taken on individual trays equipped with occlusal shafts
 after the initial registration of the central occlusal position of the mandible,
the templates are assembled using the occlusion keys
 the rims of the upper spoon are covered with a function-type silicone mass
(Xantopren Function) and they are shaped by the patient by making
movements according to the Herbst tests and movements of jaw closure,
mandible extension and retraction, lateral movements with constant
contact of the occlusal shafts of both paddles
 put a layer of the liquid impression material (Xantopren blue) on the entire
upper impression tray and take an impression with the mouth closed with
the lower tray left
 the same procedure is used for the lower impression, i.e. the upper
impression is left in the mouth

53. Marxkors impression method

54. Marxkors impression method

55. Marxkors impression method

56. Marxkors impression method

57. Impression using the Płonka
method (Wrocław method)
 with mouth closed, bite impression
 the pressure exerted on the mass should be regulated
by the strength of the patient's muscles and not by the
doctor's hand
 the impression is taken on trial dentures on a rigid
plate with artificial teeth set in the wax after recording
the occlusion.

58. Impression using the classic
method

59. Impression using the classic
method
 Tray after binding the mass

60. Impression using the classic
method

61. Impression using the classic
method
 Based on the functional impression, the technician
creates a working model
 It is important to properly prepare functional
impressions by gluing a circular approx. 4 mm wide
wax collar to protect the edge of the impression and
thus register the extent and functional shaping of the
outer part of the impression rim on the model.

65. Cast working models

66. Thank You