Theme 16

Indications and steps of cast bridges.

1. A patient is being made cast bridge denture with 17, 14 as abutments. Which wax is used for making copings on abutments?

1. *Dipping

2. Baseplate

3. Casting

4. Carving

5. Boxing

2. Main elements of CoCr alloy are: A) *cobalt and chromium; B) nickel, cobalt and chromium; C) titan, cobalt, chromium, nickel; D) cobalt, chromium, sulphur, manganese; E) cobalt, chromium, molybdenum, nickel, manganese

3. Porcelain mass doesn’t consist of: A) *marshalit; B) kaolin;

C) hard glass;

D) feldspar;

E) quartz;

4. Shrinkage of porcelain mass is: A) *about 30%; B) 15-20%; C) 20-25%; D) 10-15%;

E) 35-40%;

5. What thermal expansion coefficient of metal is allowed while making metal-ceramic crown framework?

A) *14%;

B) 16% ;

C) 18%;

D) 20% ;

E) 22%;

6. The best alloy for cast bridges is:

A) *gold

B) Co-Cr alloy

C) silver-palladium

D) chromium-nickel steel

E) silver

7. There are such laboratory stages of cast bridge making:

1. wax pattern of abutment teeth.

2. processing and polishing of metal.

3. burnout of wax and casting.

4. wax pattern of bridge body

5. making of facing.

Place the laboratory stages consistently:

À) *3 5 2 4 1

B) 1 2 3 4 5

C) 2 1 3 5 4

D) 5 1 2 4 3

E) 1 4 3 2

8. While making metal-ceramic bridge there are the following laboratory steps:

1. Wax pattern of a framework.

2. Covering the framework by ceramic mass.

3. Burning of ceramic mass.

4. Making of models

5. Casting of framework.

6. Glazing.

1. *4,1,5,2,3,6

2. 1,4,5,2,3,6

3. 5,4,1,2,3,6

4. 2,3,1,4,5,6

5. 3,1,2,4,5,6

9. Put the following laboratory procedures of cast bridge making in the correct order:

1. wax pattern of a framework

2. processing and polishing the metal framework

3. casting

4. casts pouring

А. *4,1,3,2.

В. 1,3,4,2.

С. 2,3,1,4.

D. 3,1,4,2.

Е. 2,1,4,3.

10. While making cast bridge denture dental technician poured sectional model for –

1. *Ease of modeling and fitting

2. Precise casting

3. Metal shrinkage prevention

4. Doubling the model from fireproof material

5. Wax deformation prevention

11. Patient is being made a metal-ceramic bridge denture on 45, 47, 37, 35 teeth. After teeth preparation an operator should take working impression with –

À) *“speedex”

B) “stens”

C) “stomalgyn”

D) “repeen”

E) “ortokor”

12. The patient had his teeth prepared for cast bridge denture, impression was taken. Dental technician is going to make casts:

1. *Sectional (IV class gypsum)

2. Sectional (I class gypsum)

3. Sectional (Melot)

4. Standart ( Melot)

5. Standart (Cement)

13. A patient is being made cast bridge denture with 28, 25 as abutments. Which alloy from the following will be used for casting?

1. *CoCr

2. 900 part gold

3. Stainless steel

4. Cr18 Ni10T

5. Low fusible alloy

14. A patient is being made cast bridge with 17, 15 as abutments. What is held by an operator during second appointment?

1. *Framework fitting

2. Crowns fitting

3. Pontic fitting

4. Occlusal impression

5. Fixation

15. A patient is being made cast bridge denture. An operator is checking the quality of fitting internal side of crown to the teeth. Which material is better to use for this purpose?

1. *Wash phase of silicone

2. Putty of silicone

3. Wax

4. Repeen

5. Stens

16. A patient is being made cast bridge denture. An operator is checking occlusion while fitting a framework. How it must be performed?

1. *Occlusogramm in all occlusions

2. Occlusogramm in frontal and central occlusion

3. Musticatiography

4. Gnathodynomometry

5. Myography

17. A patient had his 27, 25 teeth prepared for cast bridge denture. The marginal design of preparation is with subgingival shoulder. What material is commonly chosen for impression making?

1. *Two phase silicone

2. Polyether

3. Alginate

4. Monophase silicone

5. Hydrocolloid

18. A patient is recommended to restore dental arches with cast bridge denture. What amount of dental tissues will be removed from each tooth in average?

А. *0.5-1 mm

В. 0.3-0.5 mm

С. 1.5-2 mm

D. 0.28-0.5 mm

Е. 1-1.5 mm

19. A patient has come for a fitting test while making cast bridge denture. An operator revealed supracontact in frontal occlusion. What instrument he should use to cut metal surface?

1. *Vulcanite cutting instrument

2. Separative disk

3. Wheel-shaped cutting instrument

4. Carborund stone

5. Diamond stone

20. A patient is being planned to restore dental arches with cast bridge. Teeth preparation will be done with shoulder margin. Which cutting instrument is better to use for making a shoulder?

1. *Torpedo bur

2. Diamond head

3. Separative disk

4. Miller

5. Needle bur

21. Metal part of metal-ceramic bridge is named:

À. *framework B. facing C. clasp

D. body E. intermediate part

22. A patient is being planned to restore dental arches with cast bridge denture with 47, 45 as abutments. Examination data: low clinical crowns. What is the feature of teeth preparation in this case?

1. *Without ledge

2. 135° ledge

3. 90° ledge

4. 135° beveled ledge

5. Doesn’t matter

23. What is the purpose of varnishing dies before modeling?

1. *Compensation of metal shrinkage

2. Compensation of cement shrinkage

3. Compensation of wax shrinkage

4. For visualization of cervix

5. For ease removal of wax coping

24. An emergence profile of artificial crown axial contour that extends from the base of the gingival sulcus past the free margin of the gingiva to the height of contour should be waxed –

1. *Straight

2. Concave

3. Convex

4. Round

5. Sharp

25. A patient is being planned to perform teeth preparation for a cast bridge denture. What wall inclination you should make?

1. *3-4°

2. 1-3°

3. 10-12°

4. 5-7°

5. 9-11°