Theme 7. Main principles of teeth preparation. Armamentarium.

1. Separation of contact surfaces of tooth during preparation for acrylic crown is performed by:

À) *needle shape bur

B) Carborundum stone;

C) Round bur;

D) Inverted cone;

E) Miller;

2. The reduction of occlusal surface during preparation can be checked by:

À) *Strip of wax;

B) Gypsum models;

C) Probe;

D) Visually

E) One strip of copy-paper;

3. Electric handpieces operate at a _________.

1. *constant torque

2. variable torque and constant speed

3. constant torque and speed

4. none of the above

4. Electric handpieces use a motor with the attainable rpm primarily determined by the

_________ used.

1. *gear reduction of the motor attachment

2. gear multiplication of the motor attachment

3. gear enhancement of the turbine

4. all of the above

5. Shoulder during preparation is made with:

À) *taped bur

B) carborundum stone

C) diamond bur

D)separative disk

E) round head

5. Which instruments you should use for smoothening of sharp edges of tooth?

À) *diamond shaped head;

B) diamond stone;

C) separative disk;

D) elastic;

E) polishing head;

5. How to prevent injury of gingival papilla?

À)* gingival retraction;

B) prescription of spasmolysants;

C) use of separative disk with limitation;

D) sparing preparation of teeth;

E) use of protective carriage;

5. While reducing tooth tissues you should cut down the vertical walls of tooth on:

À) *The thickness of future crown material

B) According to the perimeter of tooth neck

C) Only equator

D) Contact point

E) Below than neck

9. Tooth preparation is not required for:

À) *Orthodontic crown

B) Compoundable crown

C) Porcelain crown

D) Acrylic crown

E) Cast crown

10. To prevent opening of pulp horn during tooth preparation you should:

À) *Not affect the areas of safety

B) Follow the rules of antiseptic

C) Follow the rules of asepsis

D) Use only centering burs

E) Make preparation quickly

11. Finishing burs fabricated from tungsten carbide have __________ than do operative burs.

1. *more flutes closer together

2. fewer flutes farther apart

3. fewer flutes closer together

4. any of the above

12. To avoid complications in pulp during preparation it is necessary NOT to follow such rules:

À) *Use a dry instrument on the dry surface of tooth

B) Interrupted preparation

C) Preparation with cooling

D) Follow the areas of tooth safety

E) Use sterile, sharp instruments

13. To avoid an injury of oral cavity soft tissues it is necessary to use:

À) *Dental mirror

B) The rules of preparation

C) Sedative drugs

D) Not to use sharp burs

E) The rules of asepsis

14. Protection of tooth after preparation could be performed with all listed above EXCEPT:

1. *glue BF-6

2. provisional crown

3. fluoride varnish

4. rinsing of oral cavity

5. varnish “Cyadent”

15. Patient is being made a crown on a 21 tooth. Subgingival preparation is conducted. When it is necessary to put a retraction cord?

À) * before preparation and making impression;

B) before try-in of a framework;

C) before fixing;

D) after try-in of framework;

E) after taking impression

16. Tooth preparation with slight taper allows avoiding:

1. *undercuts

2. decementation

3. gingiva trauma

4. balance of a construction

5. tooth overheating

17. Dentist is performing tooth preparation for an artificial crown. In order to create correct shape of prepared tooth you must hold a bur:

1. *parallel to a tooth axis

2. with 3 degree angle

3. perpendicular to a gingiva

4. perpendicular to a neck

5. with 6 degree angle

18. What shoulder location does not exist in relation to a gingival crevice?

À) *on the bottom of gingival crevice

B) above gingival crevice

C) supragingivally D) below gingiva

19. How to prevention injury of adjacent teeth during tooth preparation?

A) *use a thin metal matrix band

B) use a thin retraction cord

C) use proximal enamel of the tooth being prepared

D) use a dental mirror

E) use a thick retraction cord

20. Normal healthy dentogingival sulcus has depth up to:

À) *1 mm;

B) 0,6 mm;

C) 0,3 mm;

D) 0,8 mm;

E) 1,2 mm.

21. Teeth preparation is performed by:

À) *Diamond heads

B) Carborundum milling cutters

C) Vulcanite disks

D) Diamond rubbers

E) Metal milling cutters

22. Patient is being planned 47 tooth preparation for artificial crown. Dentist is reducing occlusal surface. What is the feature of preparation?

1. *Buccal cusps are prepared more than lingual

2. Buccal cusps are prepared as lingual

3. Lingual cusps are prepared more than buccal

4. Medial cusps are prepared more than distal

5. Medial cusps are reared less than distal

23. When preparation for artificial crown with a shoulder is not necessary?

1. *Metal swaged crown

2. Jacket-crown

3. Telescopic crown

4. Metal-ceramic crown

5. Composite crown

24. Artificial crown is being planned for a patient’s 36 tooth. While examination it was revealed that crown of 36 is short and wide. How to increase retention of a crown?

1. *Create grooves

2. Create round shoulder

3. Reduce less dental tissues

4. Reduce more dental tissues

5. –

25. Choose correct ending of a statement: if tooth with taper more than 15° is being covered with restoration –

1. *Tension in cement layer increases

2. Tension in cement layer decreases

3. Metal tension increases

4. Metal tension decreases

5. Dental tissues tension increases