Theme 6

1. Stens-03 belongs to the following group of impression materials:

1. *Impression compounds

2. Alginates

3. Impression plaster

4. Silicones

5. Polyethers

2. The setting temperature of Stens is:

   1. *35 º С.

B. 30 º С.

C. 40 º С.

D. 45 º С.

E. 25 º С.

3. All of the following impression materials belong to impression compounds except:

1. *Vokoloid

2. Masster

3. Stens-03

4. MST-03

5. Dentafol

4. Gypsum belong to the following group of impression materials:

1. *Impression plaster

2. Impression compounds

3. Alginates

4. Zinc oxide-eugenol

5. Zinc oxide-guaiacol

5. The setting time of gypsum is not influenced with:

1. *Dye filler

2. Water temperature

3. Quantity of water

4. Speed of kneading

6. Gypsum should be stored:

1. *Hermetic storage

2. Dark room

3. Low range of humidity

4. Not important

7. Which thermoplastic impression material is indicated for impressions of teeth prepared for crowns, inlays?

1. *MST-03

2. Dentafol

3. Stomaplst

4. Masster

5. Ortocor

8. Is it possible to reuse impression compound?

1. *Possible if to sterilize used material

2. Impossible in any condition

3. Possible if to mix used material with a portion of new one

4. Possible in any condition

9. What substance is accelerator of zinc oxide eugenol?

1. *Zinc acetate

2. Zinc oxide

3. Eugenol

4. Kaolin

5. Hydrogenated resin

10. The patient V., 1965 year of birth, is performed impression taking from the lower jaw with impression compound. Compound was heated till liquid state and added into impression tray with the help of brush. Which material should be added by brush?

1. *Dentafol

2. Stomaplast

3. Stens-03

4. Masster

5. MST-03

11. What is zinc oxide-eugenol indicated for?

1. *Functional impression

2. Anatomic impression

3. Auxiliary impression

4. Impression for fixed prosthodontics

12. Before pouring casts gypsum impressions should be soaked:

1. Into cold water for 5 min

2. Into cold water for 10 min

3. Into hot water for 5 min

4. Into hot water for 10 min

5. Nothing mentioned above

13. Gypsum impression pieces should be glued together with:

1. *boiled wax

2. warm wax

3. there is no difference in wax temperature

14. Advantages of impression plaster are the following except:

1. *easily detached from teeth

2. minimal shrinkage

3. not soluble in saliva

4. easily detached from tray

5. Good surface detail

15. Gypsum impression withdrawal starts from:

1. *separating tray from impression

2. distal areas

3. anterior areas

4. simultaneous

5. nothing mentioned above

16. In order to get gypsum impression from the mouth doctor should:

1. *brake it

2. pull it

3. there is no difference

4. wet it

5. do nothing

17. Disadvantage of gypsum is the following:

1. *difficult to detach from teeth

2. minimal shrinkage

3. soluble in water

4. toxic

5. not accurate surface detail

18. What increases the setting rate of zinc oxide eugenol? (3 answers)

1. *Accelerator addition

2. *Humidity

3. *Increasing of temperature

4. Decreasing of temperature

5. Eugenol

19. Retarders of gypsum crystallization are: (3 answers)

1. *Sugar

2. *Starch

3. *Glycerin

4. Sodium chlorite

5. Potassium chlorite

20. What temperature does setting rate of gypsum start to decrease at?

1. *50-100 ºC

2. 30-37ºC

3. 37-50 ºC

4. Above 100 ºC

THEME 7

1. While dipping teeth into alginate impression material doctor should:

1. *don’t press

2. slightly press on impression tray

3. permanently press on impression tray

4. make quick pressure on impression tray

5. choose different techniques

2. After taking impression using alginate the cast ideally should be poured:

1. *Immediately

2. In 2 hours

3. In a day

4. There is no difference

5. In a week

3. Disadvantage of alginate is:

2. *shrinkage

3. not soluble in saliva

4. elasticity

5. low viscosity

6. easily removed from teeth

4. Doctor chose standard impression tray for impression making with c-silicone. What is the nest step?

А. *covering the tray with adhesive

В. teeth preparation

С. mixing of putty paste

D. mixing of wash paste

E. covering teeth with cellophane

5. A lower W/P ratio if alginate increases:

A. *strength, tear resistance and consistency

B. grainy mix and consistency

C. working and setting times and flexibility

D. tear resistance, working and setting times

E. strength, grainy mix and consistency

6. Anesthesia before impression taking with c-silicone is performed for:

1. *Anesthetize tissues before using retraction cord

2. Anesthetize tissues before taking impression with putty

3. Anesthetize teeth before taking impression

4. Anesthetize teeth before preparation

5. Anesthetize tissues before taking impression with wash

7. How should alginate impression be kept before cast pouring?

1. *be covered in a damp gauze/napkin

2. Be soaked In water

3. In cellophane packet

4. be soaked in hypochlorite

5. in the air

8. A lower W/P ratio if alginate decreases:

A. *working and setting times and flexibility

B. grainy mix and consistency

C. strength, tear resistance and consistency

D. tear resistance, working and setting times

E. strength, grainy mix and consistency

9. The purpose of sodium phosphate is to:

1. *decrease setting time

2. increase setting time

3. obtain smooth model and die surfaces

4. dye

5. flavour

10. Thixotropy is –

    1. *a property of material liquefy when subjected to vibratory forces like simple shaking, and then solidify again when left standing

    2. A property of material to solidify

    3. A property of material to liquefy

    4. a property of material liquefy when subjected to vibratory forces like simple shaking

    5. a property of material liquefy when subjected to heating and then solidify again

10. Which silicones reaction of polymerization gives no by-product?

    1. *Addition

    2. Dissolution

    3. Crystallization

    4. Cross-linking

    5. Condensation

10. Is it important to use gloves of definite material while mixing C-silicones?

    1. *It is not important

    2. It is important

    3. It is important only for several brands of c-silicones

10. Working time is –

    1. *Duration from the start of mixing to the time when a test rod leaves a permanent indentation in the material upon withdrawal.

    2. Duration from the start of mixing to the time when material is viscous

    3. Duration characterizing changes of material

    4. Duration from viscous state to high viscosity

    5. Duration characterizing physical and chemical changes of material

10. Alginate impression materials are NOT used for:

    1. *Impressions for fixed prosthodontics

    2. Partial removable dentures

    3. Preliminary impressions for complete dentures

    4. Orthodontic impressions

    5. Diagnostic impressions

10. Disadvantage of C-silicones is:

    1. *Hydrophobic

    2. Ease of use

    3. Moderate tear strength

    4. Accurate

    5. Non toxic and non irritant

10. What is setting contraction of A-silicones over first 24 hours (% by Craig, 1989)?

1. *0,14 – 0,17

2. 0,18 – 0,25

3. 0,26 – 0,37

4. 0,38 – 0,60

5. 0,61 – 0,80

10. This statement is NOT advantage of silicones:

1. *Easy to remove from tray

2. Dimensional stability

3. High tear resistance

4. Good elastic recovery

5. Wide range of viscosity’s

10. There are NO such range of A-silicones viscosity:

1. *Very low

2. Low

3. Moderate

4. High

5. Very high

10. What is the influence of latex gloves on additional silicones?

1. *Increase setting time

2. Change of color

3. Decrease setting time

4. Change of flavour

5. Increase amount of sulphur

10. What can be used for alginate and silicone impressions disinfection? (mark 2 answers)