Theme 11. Indications and steps of temporary crown fabrication.

1. Provisional crowns are -

À) *Temporary crowns

B) Swaged crowns

C) Combined crowns

D) Cast crowns

E) Permanent crowns

2. Which material from the following is temporary cement?

À) *Zinc oxide-eugenol cement

B) Phosphate cement

C) Correga

D) Polycarboxilate cement

E) Composite material

3. Speed of polymerization of autopolymerized acrylic resin directly depends on:

A)*proportion of polymer and monomer; B) air humidity; C) air temperature;

D) light; E) volume of material;

4. What are the factors that provisional crown provides for defence of the pulp of vital tooth?

1 – material with low thermal conductivity; 2 – marginal adaptation; 3 – functional occlusion of restoration; 4 – nonimpinging margins; 5 – cosmetics

1. *1,2

2. 2,3

3. 1,4

4. 4,2

5. 1,3

5. Provisional restoration should require the following:

1 – strength; 2 - stable position of the crown; 3 – esthetics; 4 – protection of the pulp; 5 – occlusal function; 6 – easily cleaned; 7 – nonimpinging margins; 8 – long-life

1. *1,2,3,4,5,6,7

2. 1,2,3,4,5,7,8

3. 2,3,4,5,6,7,8

4. 3,4,5,6,7,8

5. 2,3,4,6,7,8

6. What from the following is the most correct definition for direct technique of provisional crown fabrication?

1. *Fabrication of the crown in the mouth

2. Fabrication of the crown on the model

3. Fabrication of the crown using index

4. Fabrication of the crown using impression

7. What from the following is the most correct definition for indirect technique of provisional crown fabrication?

1. *Fabrication of the crown on the model

2. Fabrication of the crown in the mouth

3. Fabrication of the crown using index

4. Fabrication of the crown using impression

8. What material is used to fabricate provisional restorations by direct technique?

1. *That doesn’t contain polymethylmethacrylate

2. Zinc oxide eugenol

3. Sinma-M

4. Acryloxide

5. Ftorax

9. What is the advantage of direct technique provisional crown fabrication?

1. *Marginal adaptation

2. Quick term of fabrication

3. Irritation of the pulp by material

4. Economics

5. Big material’s shrinkage

10. What material which used for provisional crowns fabrication produces great amount of heat?

1. *Polymethyl methacrylate

2. Polyethyl methacrylate

3. Polyvinyl methacrylate

4. Bis-acryl composite

5. Light-cured urethane dimethacrylate

11. What materials which are used for provisional crowns fabrication have less stain resistance?

1. *Bis-acryl composite, light-cured urethane dimethacrylate

2. Polymethyl methacrylate, polyvinyl methacrylate

3. Light-cured urethane dimethacrylate, polyethyl methacrylate

4. Polyvinyl methacrylate, bis-acryl composite

5. Polymethyl methacrylate, polyethyl methacrylate

12. How much is the marginal adaptation of provisional crowns made by indirect technique is better than made by direct technique?

1. *70

2. 50

3. 30

4. 15

5. 25

13. What is used to shape the provisional restoration?

1. *Impression, template

2. Waxing, impression

3. Template, waxing

4. Composite modeling, impression

5. Template, composite modeling

14. What impression materials are reasonably to use for shaping provisional restoration?

1. *Alginate, silicone

2. Alginate, gypsum

3. Gypsum, zinc-oxide eugenol

4. Impression compound, gypsum

5. Polyether, silicone

15. Choose the correct order of the steps of indirect technique for provisional crowns fabrication:

1 – crown cementation, 2 – impression taking, 3 – tooth preparation

1. *2,3,2,1

2. 2,3,1

3. 3,2,1

4. 3,2

5. 2,3,2

16. Choose the correct order of the clinical steps of direct technique for provisional crowns fabrication:

1 – resin mixing, 2 – polymerization, 3 – impression taking, 4 – tooth preparation, 5 – expression of the mixed resin into the imprint, 6 – seat the template on the teeth, 7 – remove the template, 8 – process the crown

1. *3,4,3,1,5,6,7,2,8

2. 4,3,1,5,6,2,7,8

3. 3,4,3,1,5,6,2,7,8

4. 3,4,3,1,6,5,7,2,8

5. 4,3,1,5,6,7,2,8

17. Operator is fabricating provisional restoration by direct technique. Resin has completely polymerized. What is the next clinical step?

1. *Crown processing

2. Overimpression removal from the mouth

3. Relining of the crown

4. Crown cementation

5. Crown polishing

18. Operator is fabricating provisional restoration by direct technique. He reveals a defect in marginal area after polymerization and teasing the crown from the tooth. What he should do?

1. *Reline the crown

2. Make new crown

3. Take new impression

4. Make a crown by indirect technique

5. Cement the crown

19. It was decided to fabricate temporary crowns by indirect technique. What is the first clinical procedure?

1. *Diagnostic impression

2. Teeth preparation

3. Teeth restoration

4. Anatomic impression

5. Overimpression

20. Temporary crowns are fabricated by indirect technique. The models were prepared for taking overimpression. What material from the listed below has the best qualities as for overimpression taking?

1. *Resin

2. Silicone of high viscosity

3. Silicone of low viscosity

4. Alginate

5. –

21. What materials are used for prefabricatory provisional restorations?

1. *Polycarnonate, stainless steel

2. Polymethylmethacrylate

3. Polyethylmethacrylate

4. Stainless steel

5. Polymethylmethacrylate, polycarbonate

22. Operator is fabricating provisional crown by direct technique. What the doctor should do before he or she seats the form with resin on teeth?

1. *Apply a uniform coat of petrolatum

2. Dry teeth

3. Put cotton rolls around prepared teeth

4. Prepare teeth

5. Take impression

23. Provisional crown is fabricated by indirect technique. The doctor fixed post and core cast restoration. Took impression and gave it to the dental technician. What is the next laboratory step?

1. *Pouring impression and waxing

2. Pouring the impression and taking overimpression

3. Waxing

4. Template (form) making

5. Impression pouring and packing

24. The patient is being fabricated provisional fixed denture consists of two crowns-retainers and pontic. What type of provisional restoration is better to use in this case?

1. *Custom

2. Factory

3. Aluminum caps

4. Celluloid caps

5. Polycarbonate crowns

25. What technique of provisional crowns fabrication is preferable for the dentists in the early years of practice?

1. *Indirect

2. Direct

3. Combined

4. Individual