Exercises for Part 1
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. List factors that make demands upon restorative dental materials.
- a. The corrosive nature of _________________.
- b. The ______________ and ________________ of tooth structure with changes in temperature.
- c. The stress of ____________________ forces (grinding and chewing).
- d. Compatibility with __________________ tissues.
- e. Where visible, materials must be _______________________ pleasing.
2. Select the grain size in metals that gives the most desirable properties.
- a. Small grains.
- b. Large grains.
- 3. In cast metal, the grains are:
- a. Elongated.
- b. Flattened.
4. Match the term in Column I to the definition in Column II.
(1) ___ Hardness
(2) ___ Ductility
(3) ___ Malleability
(4) ___ Flexibility
(5) ___ Elasticity
a. Permits a metal to be shaped into a thin sheet
b. Allows a metal to deform temporarily
c. Returns a metal to its original shape
d. Resistance of a metal to indentation or
e. Capacity of a metal to be stretched without
5. Match the term in Column I to the definition in Column II.
- (1) ___ Fatigue
- (2) ___ Crushing strength.
- (3) ___ Thermal conductivity
- a. Ability to transmit heat or cold
- b. Resistance to fracture under compression
- c. Fracture point after repeated stressing
6. Match the term in Column I to the definition in Column II.
- (1) ___ Cold working
- (2) ___ Strain hardening
- (3) ___ Annealing
- (4) ___ Tempering
- a. Heat softening treatment
- b. Heat hardening treatment
- c. Changing the shapes of metal at room temperature.
- d. Metal becomes stiffer after force is applied, to the point of fracture
7. Select the metallurgical process that restores properties to metals that are decreased by cold working and annealing.
- a. Cold working.
- b. Softening heat treatment.
- c. Strain hardening.
- d. Hardening heat treatment.
8. Select the metal included in dental silver alloy which has a specified percentage range of from 6 to 13 percent.
- a. Mercury.
- b. Silver.
- c. Tin.
- d. Zinc.
- e. Copper.
9. The metallic element in dental amalgam that is silver-white, liquid at room temperature, and poisonous is _______________________.
10. Dental amalgam is a:
- a. Solid mixture of silver, tin, copper, and zinc.
- b. Specially prepared silver alloy combined with mercury.
11. Which of the following ingredients of dental amalgam imparts strength, durability, and color, decreases the setting time and flow, and gives desirable setting expansion?
- a. Mercury.
- b. Copper.
- c. Silver.
- d. Zinc.
- e. Tin.
12. Which of the following ingredients of an amalgam restoration increases workability and unites with oxygen to produce a clean amalgam?
- a. Tin.
- b. Zinc.
- c. Silver.
- d. Copper.
- e. Mercury.
13. The most important physical properties of amalgam are:
- a. Flow and __________________.
- b. _________________________ change.
- c. ______________________ strength.
14. At 50 percent mercury content, the compression strength of amalgam is:
- a. 30,000 psi.
- b. 52,000 psi.
- c. 100,000 psi.
15. Which of the following is an advantage of amalgam?
- a. As it ages, corrosion products form along the interface of the restoration and the tooth.
- b. It conducts heat or cold readily.
- c. The color does not match the color of the teeth.
- d. It will tarnish with time.
16. Which dispenser in the amalgam dispensing system has four interchangeable plungers?
- a. The alloy dispenser.
- b. The mercury dispenser.
17. How long does the amalgamator take to mix one alloy pellet?
- a. 30 seconds.
- b. 20 seconds.
- c. 10 seconds.
- d. 5 seconds.
18. Select the result that is NOT caused by undertrituration.
- a. Lengthened setting time
- b. Increased expansion.
- c. Weakened amalgam.
- d. Increased shrinkage.
- 19. Complete information related to the usage of amalgam.
- a. The amalgam is taken from the capsule and placed in an _______________
- b. The process of packing an amalgam mix into a cavity preparation is called ____________________________.
- c. Sufficient packing pressure is necessary to prevent ________________ in the restoration.
- d. Immediately after condensation, ____________________ can be started with sharp instruments.
20. List four adverse effects of moisture contamination.
- a. Excessive ____________________ of amalgam.
- b. __________________________ pain.
- c. Lowered ____________ ________________.
- d. ________________formation on the ________________ of the amalgam.
21. What should you do with capsules in poor condition or cracked capsules?
- a. Store them in a closed container in a fireproof area.
- b. Cleanse them with a water coolant.
- c. Discard them IAW SOP.
22. There must be no ___________________in the part of the clinic where mercury or amalgam are used.
- a. Carpeting.
- b. Storage of materials.
- c. Source of heat.
23. How often must amalgamators be cleaned? a. Every day. b. Once a week. c. Once a month.
24. List the four types of dental cement discussed in the lesson.
- a. __________ _______________ cement.
- b. __________________________ cement.
- c. __________ ________________ cement.
- d. __________ _______________ and ____________________ cement.
25. List two ways that zinc phosphate is used.
- a. As an ___________________________ _________________
- b. As a____________________ _____________________.
26. The primary ingredients of zinc phosphate cement powder are:
- a. ___________________ ____________________.
- b. ______________________ _________________.
- 27. The ratio of the ingredients of zinc phosphate cement liquid is as follows.
- a. Two parts of _________________ _________________.
- b. One part of ___________________.
28. Zinc phosphate cement liquid should NOT be discarded when:
- a. The liquid has been left unstoppered for a long time.
- b. The liquid is discolored.
- c. The liquid is down to the last 30 percent in the bottle.
29. List advantages of zinc phosphate as a cementing medium.
- a. ____________________________ appearance.
- b. Speed and ________________ of usage.
- c. Sufficient flow to form a thin _____________________ for cementing.
- d. Low __________________ conductivity beneath a metallic restoration.
30. List disadvantages of zinc phosphate as a cementing medium.
- a. ______________________ crushing strength.
- b. __________________________ solubility in mouth fluids.
- c. __________________________ material (not suitable for visible surfaces).
- 31. The compression strength of zinc phosphate cement is between:
- a. 12,000 and 19,000 psi.
- b. 21,000 and 29,000 psi.
- c. 30,000 and 52,000 psi.
32. Zinc phosphate cement will take longer to harden when:
- a. Less powder is used.
- b. More powder is used.
- c. Powder in equal amounts is used.
33. List four actions to maintain and prolong the normal setting time for zinc phosphate cement.
- a. Keep (or lower) the temperature to between ______ and ______ F.
- b. Blend the powder _________________.
- c. Mix the powder over a ___________ _______________of the cool slab.
- d. Use a __________________ mixing time.
34. When preparing a mix of zinc phosphate cement, the powder is divided and subdivided into portions. Of the total number of portions to be mixed, how many are sixteenth portions?
- a. Six.
- b. Four.
- c. Two.
35. When mixing zinc phosphate cement, how is the liquid dispensed?
- a. With a special dropper supplied by the manufacturer.
- b. With a generic dropper supplied by the dental clinic.
36. List the segments and time rules for spatulation.
- a. Spatulate the first three segments for about ______ seconds.
- b. Spatulate the next two segments for about ______ seconds.
- c. Spatulate the final segment for ______ to ______ seconds.
37. When mix is ready for use, it should be similar in consistency to:
- a. Putty.
- b. Skim milk.
- c. Thick cream.
- d. Melted ice cream.
38. Describe what happens after the spatula is placed on the slab.
- a. The spatula is raised ______ inch(es).
- b. The mix clings in a _________ _____________ (a peak).
- c. The mix holds for _____ or _____ seconds before it breaks and gradually spreads.
39. List the uses of polycarboxylate cement.
- a. As a cementing medium of ___________ __________.
- b. As a cementing medium of ______________ ____________.
- c. As a _______________ ______________.
- d. As a base under ________________ restorations.
- e. As a ______________________ restorative material.
40. Polycarboxylate cement powder contains:
- a. Zinc oxide.
- b. Magnesium oxide, ______ to ______ percent.
- c. Aluminum oxide, ______ to ______ percent.
- d. Sometimes, a small percentage of ________.
41. Polycarboxylate cement liquid is rather thick. It has:
- a. Low molecular weight.
- b. High molecular weight.
42. List advantages of polycarboxylate cement over zinc phosphate cement.
- a. It is easier to ___________________.
- b. There is less __________________ due to thermal shock to the pulp.
43. Mixing of polycarboxylate cement is done by rapidly blending the powder and the liquid for ______ seconds on a nonporous, polymer paper mixing pad.
44. List three precautions concerning polycarboxylate cement.
- a. The mix should be used while it is still _____________, before the onset of ______________________
- b. __________________ containers should be used to store the powder and the liquid. They should be stored in a _________________ place.
- c. The interior of restorations and tooth surfaces must be free of ___________.
45. The primary use of glass ionomer cement is for permanent cementing of:
- a. ___________________.
- b. ___________________.
- c. ___________________.
- d. Orthodontic ____________________________.
46. The glass ionomer cement powder contains a mixture of __________________ glass with dry __________________________ acid.
47. List important properties of glass ionomer cement.
- a. It adheres chemically to _____________ and _______________ and, also, to _________________ tooth structure.
- b. It is well tolerated by the dental ________________ .
- c. It remains __________________ under a load.
- d. It possesses high _____________________ strength.
- e. It is simple to proportion, to _____________, to _________________, and to ______________ ______________ .
48. Describe the appearance of glass ionomer cement.
- a. It should always have a ___________________ appearance.
- b. When the surface becomes _________________, the setting reaction has started. The mix should be discarded.
49. For glass ionomer cement, why is it important never to exceed the working time? Exceeding the working time will result in __________ of ____________ to enamel and dentin.
50. The normal ratio of powder to liquid for glass ionomer cement is:
- a. One level scoop of powder to two drops of liquid.
- b. Two drops of liquid to one heaping scoop of powder.
51. In order to produce precise and uniform drops from the liquid bottle for glass ionomer cement, what do you have to do?
_______________ it __________________
52. Complete information related to mixing glass ionomer cement.
- a. Powder is incorporated into the liquid in_____ or_____ large increments.
- b. Each portion of the powder is added to the liquid __________ ____________
- c. The mix should be completed in about _____ seconds, at room temperature.
53. For glass ionomer cement, you know that the right consistency is obtained when the spatula is raised from the glass slab and the material breaks away at:
- a. 1/4 inch.
- b. 1/2 inch.
- c. 1 inch.
- d. 1 1/2 inches.
54. Should glass ionomer cement be inserted close to the pulp?
- a. Yes.
- b. No.
55. Is it a requirement to set in place a calcium hydroxide liner before inserting glass ionomer cement?
- a. Yes.
- b. No.
56. List potential hazards of glass ionomer cement.
- a. Some people may have an _________ _____________ to glass ionomer cement.
- b. Powder in the__________ may cause ____________ due to foreign body reaction.
- c. If you _______________ some of liquid that is used to mix glass ionomer cement, you will probably get some localized irritation.
57. It is known that glass ionomer cement adheres to wet tooth structure. Enamel and dentin _____________clean and dry before application.
- a. Have to be.
- b. Don't have to be.
58. List the clinical uses of zinc oxide and eugenol.
- a. For treatment _________________.
- b. As a _________________ cementing medium.
- c. As an intermediate __________________.
- d. For __________________ capping.
- e. As a _______________ _________________ or dressing.
59. According to NBS specifications, what is the percentage of zinc oxide powder required for zinc oxide and eugenol cement?
- a. 70 to 100 percent.
- b. 70 to 90 percent.
- c. 60 to 90 percent.
- d. 60 to 80 percent.
60. Oil of __________ contains 82 percent eugenol.
- a. Cinnamon.
- b. Oranges.
- c. Cloves.
- d. Bay.
61. Which dental cement is more likely to be used when there is pulpitis, advanced caries, or fractured teeth?
- a. Polycarboxylate.
- b. Zinc oxide and eugenol.
- c. Glass ionomer.
- d. Zinc phosphate.
62. Select the dental cement with the lower crushing strength that may be used to provide insulation between metallic restorations and vital tooth structures. (It may be used alone or in combination with another dental cement.)
- a. Zinc phosphate.
- b. Polycarboxylate.
- c. Glass ionomer.
- d. Zinc oxide and eugenol.
Solutions to Exercises for Part 1
- 1. a. saliva b. expansion; contraction c. masticatory d. living e. esthetically
- 2. a
- 3. b
- 4. (1) d (2) e (3) a (4) b (5) c
- 5. (1) c (2) b (3) a
- 6. (1) c (2) d (3) a (4) b
- 7. d
- 8. e
- 9. mercury
- 10. b
- 11. c
- 12. b
- 13. a. creep b. Dimensional c. Compression
- 14. b
- 15. a
- 16. b
- 17. c
- 18. d (
- 19. a. amalgam cup b. condensation c. voids d. carving
- 20. a. expansion b. Postoperative c. crushing strength d. Blister; surface
- 21. c
- 22. a
- 23. b
- 24. a. Zinc phosphate b. Polycarboxylate c. Glass ionomer d. Zinc oxide and eugenol
- 25. a. intermediate base. b. cementing medium.
- 26. a. Zinc oxide. b. Magnesium oxide.
- 27. a. phosphoric acid. b. water. (
- 28. c
- 29. a. Inconspicuous b. ease c. layer d. thermal
- 30. a. Low b. Slight c. Opaque
- 31. a
- 32. a
- 33. a. 65° and 75°. b. slowly. c. large area d. longer
- 34. c
- 35. a
- 36. a. 15 b. 20 c. 30 to 35
- 37. d
- 38. a. one inch b. thin thread c. one or two
- 39. a. cast alloy b. porcelain restorations c. cavity liner d. metallic e. temporary
- 40. b. 1 to 5 c. 10 to 40 d. fluoride
- 41. b
- 42. a. manipulate b. trauma
- 43. 30 to 40
- 44. a. glossy; cobwebbing b. Stoppered; cool c. saliva
- 45. a. Inlays. b. Crowns. c. Bridges. d. band/brackets.
- 46. aluminosilicate; polymaleic
- 47. a. enamel and dentin; wet b. pulp c. rigid d. compressive e. mix; apply; clean up
- 48. a. glossy b. dull
- 49. loss of adhesion
- 50. a
- 51. Hold it vertically.
- 52. a. 2 or 3 b. all at once. c. 60 (
- 53. b
- 54. b
- 55. a Yes, where the dentin is thin, in deep cavities, or where the pulp is involved. b No, in other cases.
- 56. a. allergic reaction b. eyes; irritation c. drink (OR ingest)
- 57. a
- 58. a. restoration b. temporary c. base. d. pulp e. surgical packing
- 59. a
- 60. c
- 61. b
- 62. d