About Lifelong Learning - Contact Us - DonateFree-Ed.Net Home   Bookmark and Share

Exercises for Part 3

 Answer the following exercises by marking the lettered response that best answers the question or best completes the incomplete or by writing the answer in the space provided.

After you have completed all the exercises, turn to "Solutions to Exercises" at the end of the lesson and check your answers.

1. Select the dental material below that is 1 part calcium sulfate and 2 parts water.

a. Hydrocolloid impression materials.
b. Calcium hydroxide.
c. Modeling plastic.
d. Dental wax.
e. Gypsum.

2. Which of the following cast materials is processed by steam heat under pressure?

a. Plaster of Paris.
b. Artificial stone.

3. What percentage of water is removed from the raw material to produce plaster of paris or artificial stone?

a. 100 percent.
b. 75 percent.
c. 50 percent.
d. 33 percent.

4. Which of the following has particles that are rough, irregular, and porous?

a. Plaster of paris.
b. Artificial stone.

5. The psi for artificial stone is:

a. 2,600.
b. 5,000.
c. 7,500.
d. 12,000.

6. Match the use made of the product in Column I to the product in Column II.

COLUMN I

(1) ____ Make master casts

(2) ____ Make matrices for prosthodontic

restorations

(3) ____ Make dies

(4) ____ Attach casts to articulators

(5) ____ Prismatic, more regular in shape, dense,

nonporous.

(6) ____ Rough, irregular, porous.

COLUMN II

a. Plaster of Paris

b. Artificial stone

7. Complete information related to the steps in the sequence of mixing either plaster of Paris or artificial stone.

a. Obtain a clean, dry ______________ bowl.
b. Obtain a ________________ spatula.
c. _______________ the can of powder before mixing.
d. _____________ is measured and poured into the bowl.
e. Powder is _______________ into the water.
f. All the powder from the ___________ of the bowl must be included in the mix.
g. Avoid trapping ______________________

8. Describe the process of spatulation used in mixing gypsum products.

a. With the spatula, stir the mix for _____ to _____ seconds.
b. Use a _____________ or _____________ motion.
c. _________________ the mix will entrap air bubbles and weaken the cast.
d. ____________ the mixed material in the bowl to remove trapped air bubbles.

9. Initial setting time for plaster of paris is:

a. 5 to 10 minutes.
b. 8 to 10 minutes.

10. Following the initial setting time,__________ becomes hard enough to hold for carving.

a. Plaster of Paris.
b. Artificial stone.

11. Final setting time for artificial stone, depending of the type mixed, is:

a. 10 to 25 minutes.
b. 25 to 45 minutes.

12. List the methods used to hasten the setting time for gypsum products.

a. Use ______________ water.
b. Mix for a ______________ period of time.
c. Use a ___________________ accelerator.
d. Use warm water, up to __________ F.

13. Soaking the cast for several hours in a solution of borax will increase the surface hardness of:

a. Plaster of Paris.
b. Artificial stone.

14. Match the common use in Column I to the appropriate dental wax in Column II.

COLUMN I

(1) ____ Used to prepare patterns for crowns
(2) ____ Used for making occlusal rims
(3) ____ Holds together broken pieces of a denture
(4) ____ Adapts impression trays for individual impressions
5) ____ Forms a box around impressions
(6) ____ Used in relining or rebasing dentures

COLUMN II

a. Utility wax
b. Boxing wax
c. Low-fusing impression wax.
d. Inlay casting wax.
e. Baseplate wax
f. .Sticky wax

15. Match the shape, color, and/or size in Column I to the appropriate dental wax in Column II.

COLUMN I

(1) ____ Blue, green, ivory, and deep purple sticks
(2) ____ Red or pink sheets (3" X 6")
(3) ____ Hexagonal sticks, orange or purple in color
(4) ____ Stick form (red color) or rope form.
(5) ____ Red strips (1 1/2" X 12")
COLUMN II
a. Sticky wax
b. Utility wax
c. Boxing wax
d. Inlay casting wax
e. Baseplate wax

16. Select the dental wax that remains hard both at mouth temperature and at room temperature.

a. Utility wax.
b. Disclosing wax.
c. Boxing wax.
d. Baseplate wax.
e. Low-fusing impression wax.

17. Select the dental wax that is pliable enough at room temperature to use without heating.

a. Inlay casting wax.
b. Baseplate wax.
c. Sticky wax.
d. Disclosing wax.
e. Utility wax.

18. What dental wax is used to determine unequal pressure points in a denture that may cause discomfort to a patient?

a. Sticky wax.
b. Utility wax.
c. Disclosing wax.
d. Low-fusing impression wax.

19. Which dental wax permits detailed carving without flaking or chipping and can be manipulated in the mouth without injury to oral tissues?

a. Boxing wax.
b. Inlay casting wax.
c. Utility wax.
d. Low-fusing impression wax.
e. Baseplate wax.

20. Which dental wax must be capable of holding porcelain or acrylic teeth in position both at normal room temperature and at mouth temperature?

a. Baseplate wax.
b. Sticky wax.
c. Inlay casting wax.
d. Boxing wax.
e. Low-fusing impression wax.

21. Which dental wax is often used in relining or rebasing complete and partial dentures, but must be handled with care because it is easily distorted?

a. Baseplate wax.
b. Disclosing wax.
c. Inlay casting wax.
d. Sticky wax.
e. Low-fusing impression wax.

22. Which dental wax is usually supplied either in stick form (red in color) or in rope form?

a. Inlay casting wax.
b. Utility wax.
c. Boxing wax.
d. Sticky wax.
e. Baseplate wax.

23. When making a cast (model), which wax is used to limit the flow of plaster of Paris or artificial stone gypsum material?

a. Disclosing wax.
b. Utility wax.
c. Boxing wax.
d. Inlay casting wax.
e. Sticky wax.

24. Complete information related to impression materials.

a. An impression is a _________ reproduction of a given area of the oral cavity.
b. Impression material must be inserted into the mouth while it is too ________ to retain its ________________ .
c. ___________ ___________ carry the impression material to the mouth and provide a _____________ base to hold it against the tissues until it hardens.
d. Stock trays may be ___________________ for each individual patient.

25. Describe some requirements for impression material.

a. Impression material should ___________ or be ____________ at a temperature that will not injure the oral tissue.
b. Impression material should set within _____ to_____ minutes, at body temperature.
c. It must retain an accurate ______________________n it solidifies and is withdrawn from the mouth.
d. After solidifying, it must not _________________h a sharp knife at room temperature.

26. Which type of impression material softens when warmed and hardens when cooled, with no change in chemical makeup?

a. Rigid.
b. Elastic.
c. Thermoplastic.

27. Which type of impression material expands and contracts with no change in structure or shape?

a. Rigid.
b. Elastic.
c. Thermoplastic.

28. Borax and potassium sulfate are inert substances used in:

a. Impression paste.
b. Alginate-type hydrocolloid.
c. Synthetic rubber base impression material.
d. Agar-type hydrocolloid.

29. Select the impression material for which it is important to pour the cast immediately after an impression is made.

a. Agar-type hydrocolloid.
b. Synthetic rubber base impression material.
c. Alginate-type hydrocolloid.
d. Modeling plastic.
e. Impression paste.

30. Tubes of agar-type hydrocolloid impression material must be softened by heating in boiling water, to the recommended temperature of:

a. 115 F.
b. 120 F.
c. 145 to 155 F.

31. A hydrocolloid impression always undergoes stress during removal. Which of the following actions is less likely to cause fracturing or permanent distortion?

a. A gentle, prolonged strain.

b. An abrupt, brief strain.

c. Removal from over undercut areas by "teasing."

32. Calcium sulfate is the chemical reactor for:

a. Agar-type hydrocolloid.
b. Type one synthetic rubber base impression material.
c. Alginate-type hydrocolloid.
d. Type two synthetic rubber base impression material.

33. Select the impression material that uses water and powder in a one to one ratio.

a. Synthetic rubber base impression material.
b. Modeling plastic.
c. Agar-type hydrocolloid.
d. Impression paste.
e. Alginate-type hydrocolloid.

34. Of the two types of synthetic rubber base impression materials, type one refers to a synthetic rubber base of:

a. Silicone.
b. Polysulfide.

35. Select the impression material that needs a tray adhesive to prevent it from pulling away from the tray.

a. Agar-type hydrocolloid.
b. Modeling plastic.
c. Alginate-type hydrocolloid.
d. Synthetic rubber base impression material.

36. Which of the following impression materials is easier to access and to use?

a. Silicon rubber base impression material.
b. Agar-type hydrocolloid.
c. Polysulfide rubber base impression material.
d. Alginate-type hydrocolloid.
e. Modeling plastic.

37. Select the impression material for which it is important to pour the cast within 30 minutes after an impression is made?

a. Agar-type hydrocolloid.
b. Synthetic rubber base impression material.
c. Alginate-type hydrocolloid.
d. Modeling plastic.
e. Impression paste.

38. Which of the following impression materials is supplied in stick form, or as wafers or cakes, and uses various colors to indicate different softening temperature ranges?

a. Synthetic rubber base impression material.
b. Agar-type hydrocolloid.
c. Impression paste.
d. Alginate-type hydrocolloid.
e. Modeling plastic.

39. Select the impression material used for rebase impressions for both complete and partial dentures and that is also used to provide a lining for a complete denture baseplate.

a. Synthetic rubber base impression material.
b. Modeling plastic.
c. Agar-type hydrocolloid.
d. Impression paste.
e. Alginate-type hydrocolloid.

40. Which impression material is composed of shellac, talc, and glycerides derived from certain tallow oils?

a. Modeling plastic.
b. Agar-type hydrocolloid.
c. Impression paste.
d. Alginate-type hydrocolloid.
e. Synthetic rubber base impression material.

Solutions to Exercises for Part 3

1. e
2. b
3. b
4. a
5. c
6. (1) b (2) a (3) b (4) a (5) b (6) a
7. a. rubber b. plastic c. Agitate d. Water. e. sifted f. sides g. air bubbles
8. a. 30 to 60 b. knifing; stirring c. Whipping d. Vibrate
9. a
10. a
11. b
12. a. less b. longer c. chemical d. 85
13. b
14. (1) d (2) e (3) f (4) a (5) b (6) c
15. (1) d (2) e (3) a (4) b (5) c
16. d
17. e
18. c
19. b
20. a
21. e
22. b
23. c
24. a. negative b. soft; shape c. Stock trays; rigid d. fabricated
25. a. flow; pliable b. 2 to 4 c. reproduction d. flake
26. c
27. b
28. d
29. a
30. c
31. b
32. c
33. e
34. a
35. d
36. c
37. b
38. e
39. d
40. a

 

 

 

David L. Heiserman, Editor

Copyright   SweetHaven Publishing Services
All Rights Reserved

Revised: June 06, 2015