Dental Materials Foundations And Applications11th Edition by Powers - Test Bank

Dental Materials Foundations And Applications11th Edition by Powers – Test Bank

 

Instant Download – Complete Test Bank With Answers

 

 

Sample Questions Are Posted Below

 

Chapter 05: Dental Amalgam

Powers: Dental Materials, 11th Edition

 

MULTIPLE CHOICE

 

1. Which component of dental amalgam exists as a liquid in the capsule before trituration?

a.	Tin
b.	Silver
c.	Copper
d.	Mercury

 

 

ANS:  D

 

	Feedback
A	Tin metals are solid powders.
B	Silver metals are solid powders.
C	Copper metals are solid powders.
D	Mercury is the sole liquid in the capsule.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

2. A freshly mixed mass of amalgam has a puttylike consistency for _____ minutes.

a.	1 to 2
b.	4 to 5
c.	9 to 10
d.	15

 

 

ANS:  A

 

	Feedback
A	A freshly mixed mass of amalgam has a puttylike consistency for 1 to 2 minutes. The amalgam must be manipulated into the cavity preparation during this time. The amalgam progresses to a carvable consistency for an additional 2 to 4 minutes.
B	This time is beyond the reaction limits, and carving after that point could result in fracture.
C	This time is beyond the reaction limits, and carving after that point could result in fracture.
D	This time is beyond the reaction limits, and carving after that point could result in fracture.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   1

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

3. Which of the following is not an advantage of dental amalgam when contrasted with direct resin composite?

a.	Longevity
b.	Superior esthetics
c.	Marginal integrity in subgingival areas
d.	Ease of placement in diverse clinical situations

 

 

ANS:  B

 

	Feedback
A	Longevity decreases when using an esthetic material.
B	Alternate restorative materials such as direct composite suffer from clinical problems such as expense, shorter longevity, and technique sensitivity. However, amalgams are not considered esthetic materials.
C	Marginal integrity decreases when using an esthetic material.
D	Ease of placement decreases when using an esthetic material.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   4

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

4. High-copper amalgam has about _____ wt % copper.

a.	3
b.	5 to 10
c.	13 to 30
d.	30 to 40
e.	40 to 50

 

 

ANS:  C

 

	Feedback
A	Low-copper amalgams have a copper content less than 13 wt % and are rarely used today.
B	Low-copper amalgams have a copper content less than 13 wt % and are rarely used today.
C	High-copper amalgam has about 13 to 30 wt % copper.
D	This percentage is far beyond the set parameters for copper content in amalgam.
E	This percentage is far beyond the set parameters for copper content in amalgam.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

5. High-copper amalgams have __________________ than low-copper amalgams.

a.	more corrosion
b.	higher strength
c.	better longevity
d.	A and C are correct.
e.	B and C are correct.

 

 

ANS:  E

 

	Feedback
A	High-copper amalgams have higher strength, less corrosion, and better longevity than low-copper amalgams.
B	B and C are correct.
C	B and C are correct.
D	High-copper amalgams have higher strength, less corrosion, and better longevity than low-copper amalgams.
E	B and C are correct.

 

 

DIF:    Comprehension                               REF:   p.  58              OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

6. Which component of earlier low-copper amalgam caused a significant, unacceptable expansion of amalgam when it was contaminated with moisture during placement?

a.	Mercury
b.	Copper
c.	Silver
d.	Zinc
e.	Tin

 

 

ANS:  E

 

	Feedback
A	Mercury elements are used in today’s dental amalgam.
B	Copper elements are used in today’s dental amalgam.
C	Silver elements are used in today’s dental amalgam.
D	Zinc causes a significant, long-term, and clinically unacceptable expansion of the amalgam when it is contaminated with moisture during placement. Such immediate expansion may fracture teeth.
E	Tin elements are used in today’s dental amalgam.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

7. An admixed dental amalgam contains _______________ shaped alloy powder particles.

a.	only irregularly
b.	only spherically
c.	neither irregularly shaped nor spherically
d.	a mixture of irregularly shaped and spherically

 

 

ANS:  D

 

	Feedback
A	Irregularly shaped alloy particles are used in conjunction with spherical particles.
B	Spherically shaped particles require more mercury and will set faster.
C	Irregularly shaped alloy particles are used in conjunction with spherical particles.
D	An admixed dental amalgam alloy contains a mixture of irregularly shaped and spherical silver alloy powder particles.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

8. Which of the following statements is true of admixed amalgam in contrast with spherical amalgam? Admixed amalgams

a.	contain only irregularly shaped particles, not spherically shaped particles.
b.	require more condensation force than spherical amalgams.
c.	require less mercury than spherical amalgams.
d.	set somewhat faster than spherical amalgams.

 

 

ANS:  B

 

	Feedback
A	Admixed amalgams are a combination of irregular and spherical particles.
B	Admixed amalgams require more condensation force than spherical amalgams. This property is considered an advantage to obtain good proximal contacts.
C	Admixed amalgams require more mercury.
D	Spherical amalgams set somewhat faster than admixed amalgams.

 

 

DIF:    Analysis         REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

9. Which of the following elements is a liquid at room temperature?

a.	Beryllium
b.	Mercury
c.	Gallium
d.	Sodium
e.	Lead

 

 

ANS:  B

 

	Feedback
A	Beryllium is a solid.
B	Mercury is the only metallic element in the periodic table that is a liquid at room temperature.
C	Gallium melts at slightly above room temperature.
D	Sodium is a solid.
E	Lead is a solid.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

10. Which of the following delivery methods for silver amalgam exposes the staff to the least amount of mercury?

a.	Mercury added to alloy particles and mixed with a mortar and pestle
b.	Silver alloy powder and mercury sealed into a disposable hard plastic capsule
c.	Powder compressed into tablets and mixed with mercury in a reusable mixing capsule
d.	None of the above

 

 

ANS:  B

 

	Feedback
A	A premeasured capsule is the recommended method of dispensing amalgam.
B	The precapsulated method provides the proper ratio of alloy powder to mercury, limits exposure to mercury of the dental staff, and keeps the mercury clean.
C	A premeasured capsule is the recommended method of dispensing amalgam.
D	A premeasured capsule is the recommended method of dispensing amalgam.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   3

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

11. Elimination of which compound in the gamma-2 phase of amalgam setting increases clinical longevity in today’s high-copper amalgam restorations?

a.	Silver–tin
b.	Copper–tin
c.	Mercury–tin
d.	Silver–copper

 

 

ANS:  B

 

	Feedback
A	Silver–tin is not a component of the gamma-2 phase.
B	Elimination the mercury–tin compound during the gamma-2 phase increases the clinical longevity in today’s high-copper amalgam restorations.
C	Copper–tin is not a component of the gamma-2 phase.
D	Silver–copper is not a component of the gamma-2 phase.

 

 

DIF:    Comprehension                               REF:   p.  61              OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

12. In the set mass of amalgam, original silver alloy particles comprise over ____% of the volume.

a.	10
b.	25
c.	50
d.	75
e.	90

 

 

ANS:  C

 

	Feedback
A	Ten is too low to be useful.
B	Twenty-five is too low to be useful.
C	In the set mass of amalgam, original silver alloy particles comprise over 50% of the volume of the material. The set volume is significant to the strength and corrosion resistance of the product.
D	Seventy-five is too high.
E	Ninety is too high.

 

 

DIF:    Knowledge     REF:   p.  59             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

13. ________ mercury vapor is released from dental amalgam per day, as a result of chewing.

a.	1 to 2 µg
b.	2 to 4 wt %
c.	50%
d.	No

 

 

ANS:  A

 

	Feedback
A	In practice, minute amounts of mercury vapor (approximately 1 to 2 µg per day) are released as a result of chewing.
B	This is the weight of copper content.
C	This is the weight of silver by volume.
D	Small amounts of mercury vapor are released while chewing.

 

 

DIF:    Knowledge     REF:   p.  60             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

14. Which phase is absent in a high-copper amalgam?

a.	g
b.	g1
c.	h
d.	g2

 

 

ANS:  D

 

	Feedback
A	This phase remains in a high-copper amalgam setting.
B	This phase remains in a high-copper amalgam setting.
C	This phase remains in a high-copper amalgam setting.
D	Gamma-2 (g2) is absent in a high-copper amalgam.

 

 

DIF:    Knowledge     REF:   p.  65             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

15. In its reacted state, little mercury is released from an amalgam. Little free mercury is available to be released from a set amalgam.

a.	Statement 1 is correct; statement 2 is correct.
b.	Statement 1 is correct; statement 2 is incorrect.
c.	Statement 1 is incorrect; statement 2 is correct.
d.	Statement 1 is incorrect; statement 2 is incorrect.

 

 

ANS:  A

 

	Feedback
A	Both statements are correct.
B	Both statements are correct.
C	Both statements are correct.
D	Both statements are correct.

 

 

DIF:    Comprehension                               REF:   p.  60              OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

16. What would insufficient strength in a dental amalgam lead to?

a.	Tarnish
b.	Fracture
c.	Expansion
d.	Condensation

 

 

ANS:  B

 

	Feedback
A	Tarnish is a surface reaction.
B	Insufficient strength may lead to bulk fracture or marginal fracture requiring replacement.
C	Some expansion and contraction is expected during the setting phases.
D	Condensation relates to placement.

 

 

DIF:    Knowledge     REF:   p.  61             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

17. Which of the following statement(s) is(are) true of the property of creep for amalgam restorations?

a.	High-copper amalgams have values of creep far above old low-copper amalgams.
b.	It is associated with the breakdown of marginal integrity.
c.	The ANSI/ADA requires that creep be less than 3%.
d.	A, B, and C are true.
e.	B and C are true.

 

 

ANS:  E

 

	Feedback
A	High-copper amalgams have values of creep far below old low-copper amalgams and the ANSI/ADA limits.
B	Creep is associated with the breakdown or marginal integrity, and the ANSI/ADA requires that creep be less than 3%.
C	Creep is associated with the breakdown or marginal integrity, and the ANSI/ADA requires that creep be less than 3%.
D	A and C are correct answers.
E	A and C are correct answers.

 

 

DIF:    Knowledge     REF:   p.  64             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

18. What is tarnish?

a.	A surface phenomenon
b.	Equivalent to corrosion
c.	A destructive process that eventually leads to failure of the restoration
d.	The result of chemical reactions that penetrate into the body of the amalgam

 

 

ANS:  A

 

	Feedback
A	Tarnish is a surface phenomenon.
B	Corrosion and tarnish are both prominent reactions of dental amalgam.
C	Corrosion is the result of chemical reactions that penetrate into the body of the material and eventually lead to failure of the restoration.
D	Corrosion is the result of chemical reactions that penetrate into the body of the material and eventually lead to failure of the restoration.

 

 

DIF:    Knowledge     REF:   p.  65             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

19. What is the correct order for the manipulation of amalgam?

a.	Carving, condensation, mixing, and finishing
b.	Condensation, finishing, mixing, and carving
c.	Mixing, condensation, carving, and finishing
d.	Mixing, finishing, condensation, and carving

 

 

ANS:  C

 

	Feedback
A	These tasks are out of order and not viable.
B	These tasks are out of order and not viable.
C	The correct order for manipulation of amalgam is mixing, condensation, carving, and finishing.
D	These tasks are out of order and not viable.

 

 

DIF:    Analysis         REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

20. How will under-triturated amalgam appear?

a.	Dull
b.	Soupy
c.	Crumbly
d.	A and C
e.	B and C

 

 

ANS:  D

 

	Feedback
A	Under-triturated amalgam is dull and crumbly.
B	Over-triturated amalgam is wet or soupy.
C	A and C are correct answers.
D	A and C are correct answers.
E	A and C are correct answers.

 

 

DIF:    Knowledge     REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

21. Why are ultrasonic condensers discouraged for condensation of amalgam?

a.	Increase the evaporation of mercury from the setting amalgam
b.	Provide insufficient condensation force
c.	Apply excessive condensation forces
d.	Traumatize the dental pulp

 

 

ANS:  A

 

	Feedback
A	Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.
B	Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.
C	Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.
D	Ultrasonic condensers are discouraged because they increase the evaporation of mercury from the setting amalgam.

 

 

DIF:    Knowledge     REF:   p.  67             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

22. Which of the following is the most likely route of entry for mercury into the patient and dental personnel during the manipulation of amalgam?

a.	Absorption in the gut
b.	Contact through skin
c.	The lungs as a vapor
d.	Intraoral absorption

 

 

ANS:  C

 

	Feedback
A	Gut absorption is a route for exposure, but it is less common when good mercury hygiene is used.
B	Skin may be a route for exposure, but it is less common when good mercury hygiene is used.
C	The most likely route of entry of mercury into the patient and dental personnel is through the lungs as a vapor.
D	Intraoral absorption is a route for exposure, but it is less common when good mercury hygiene is used.

 

 

DIF:    Knowledge     REF:   p.  69             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

23. How should amalgam scrap be handled?

a.	Flushed down the drain with ample water
b.	Stored in a sealed container in the refrigerator
c.	Disposed of in the trash with other daily refuse
d.	Stored in a sealed container containing x-ray developer
e.	Stored in a sealed container containing x-ray fixer or another reducing agent

 

 

ANS:  E

 

	Feedback
A	The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.
B	The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.
C	The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.
D	Amalgam scrap should be stored in a sealed container containing x-ray fixer or another reducing agent.
E	The office should have a comprehensive plan for mercury hygiene, including an amalgam separator to limit mercury efflux into the water waste. Scrap amalgam in the trash may end up in landfills and contaminate groundwater.

 

 

DIF:    Application    REF:   p.  69             OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

24. The maximum permittable mercury vapor level established by OSHA is _____ mg/m per 40-hour week.

a.	0.05
b.	0.5
c.	5
d.	50

 

 

ANS:  A

 

	Feedback
A	The maximum permittable mercury vapor level established by OSHA is 0.05 mg/m per 40-hour week.
B	That limit is well above established OSHA guidelines.
C	That limit is well above established OSHA guidelines.
D	That limit is well above established OSHA guidelines.

 

 

DIF:    Knowledge     REF:   p.  69             OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

25. When should high-volume evacuation be used with dental amalgam?

a.	Placing
b.	Polishing
c.	Removing
d.	Doing all of the above

 

 

ANS:  D

 

	Feedback
A	The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.
B	The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.
C	The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.
D	The use of high-volume evacuation during placement, polishing, and removal of amalgam restorations reduces the exposure of the patient and the dental team to mercury vapor.

 

 

DIF:    Comprehension                               REF:   p.  69              OBJ:   9

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

26. Which of the following statements is correct regarding today’s dental amalgam?

a.	It is high in zinc.
b.	It is low in copper.
c.	It has high longevity.
d.	It has placement issues.

 

 

ANS:  C

 

	Feedback
A	Today’s amalgams are low in zinc or zinc free.
B	Today’s amalgams are high in copper.
C	Amalgam is a viable clinical choice where longevity, ease of placement, and clinical performance are paramount, especially when clinical conditions are challenging.
D	Today’s amalgams work well in difficult placement challenges.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   1

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

27. At 1 day after placement, amalgam’s tensile strength most closely resembles which human structure?

a.	Bone
b.	Dentin
c.	Enamel
d.	Cementum

 

 

ANS:  B

 

	Feedback
A	The strengths of bone and cementum are similar.
B	The tensile strength of amalgam at 1 day is approximately the same as human dentin.
C	Enamel is harder than dentin.
D	The strengths of bone and cementum are similar.

 

 

DIF:    Knowledge     REF:   p.  61             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

28. On average, how much copper is in today’s dental alloy?

a.	4%
b.	10%
c.	20%
d.	50%

 

 

ANS:  C

 

	Feedback
A	This is lower than the average amount used in today’s dental alloy.
B	This is lower than the average amount used in today’s dental alloy.
C	Historically, the silver alloy used in dental amalgams had low (2 to 4 wt %) amounts of copper. These alloys were combined with mercury to form low-copper amalgam. However, the development of silver alloys with higher (13% to 30%, generally about 20%) copper has replaced low-copper alloys, because high-copper alloys produce amalgams with higher strength, less corrosion, less creep, and better longevity at the margins.
D	This is an excessive amount of copper and would not be considered.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

29. Which of the following is incorrect regarding admixed alloy?

a.	It makes better proximal contacts.
b.	It is a mixture of particles.
c.	It is easy to condense.
d.	It is easier to carve.

 

 

ANS:  B

 

	Feedback
A	This is a correct statement.
B	If a mixture of particles is used, the alloy is referred to as an admixed alloy. Amalgams containing irregular particles with or without spherical particles added require greater packing or condensation forces during placement than amalgams with spherical particles alone. Most practitioners feel that amalgams containing irregular particles produce better proximal contacts and are easier to carve.
C	This is a correct statement.
D	This is a correct statement.

 

 

DIF:    Knowledge     REF:   p.  58             OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

30. Which of the following is incorrect regarding spherical alloy?

a.	It is easy to condense.
b.	It sets faster than admixed amalgam.
c.	It requires more mercury than admixed amalgam.
d.	It makes better proximal contacts than admixed amalgam.

 

 

ANS:  A

 

	Feedback
A	Spherical amalgams require less mercury and set somewhat faster than admixed amalgams. Practitioners generally select either a spherical or admixed amalgam, depending on the clinical situation. The importance of proper manipulation of each type cannot be overemphasized. For example, if a condensation force that is appropriate for a spherical amalgam is applied to an admixed amalgam, the restoration will likely contain voids and lack adequate proximal contacts.
B	This is a correct statement.
C	This is a correct statement.
D	This is a correct statement.

 

 

DIF:    Comprehension                               REF:   p.  59              OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

31. Mercury is liquid at room temperature. It is one of two liquid metallic elements on the periodic table.

a.	Statement 1 is correct; statement 2 is correct.
b.	Statement 1 is correct; statement 2 is incorrect.
c.	Statement 1 is incorrect; statement 2 is incorrect.
d.	Statement 1 is incorrect; statement 2 is correct.

 

 

ANS:  B

 

	Feedback
A	Statement 1 is correct, and statement 2 is incorrect.
B	Mercury is a dense metal (density = 13.5 g/mL) and the only metallic element in the periodic table that is a liquid at room temperature.
C	Statement 1 is correct, and statement 2 is incorrect.
D	Statement 1 is correct, and statement 2 is incorrect.

 

 

DIF:    Comprehension                               REF:   p.  59              OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

32. Which of the following is a correct assessment regarding mercury vapor in amalgam?

a.	Higher release may occur during the setting reaction.
b.	Higher release may occur during removal of old amalgams.
c.	Higher release may occur if the amalgam is heated above 80° C.
d.	All of the above are correct statements.

 

 

ANS:  D

 

	Feedback
A	A, B, and C are all correct statements.
B	A, B, and C are all correct statements.
C	A, B, and C are all correct statements.
D	Higher release may occur during the setting reaction, during removal of old amalgams, or if the amalgam is heated above 80° C.

 

 

DIF:    Comprehension                               REF:   p.  60              OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

33. The sum of ________________________ determines the overall dimensional change of an amalgam restoration.

a.	compressive strength plus condensation
b.	contraction and expansion during setting
c.	compressive strength plus tensile strength
d.	the amount of tarnish and corrosion produced

 

 

ANS:  B

 

	Feedback
A	The strength of an amalgam must withstand oral forces. Insufficient strength may lead to bulk fracture or marginal fracture requiring replacement.
B	Although it is somewhat confusing, expansion and contraction occur simultaneously during the setting reaction of amalgam. The dissolution of the alloy particles into the liquid mercury generally leads to contraction, whereas the formation of matrix products causes expansion. The overall dimensional change is therefore the sum of these two processes.
C	When amalgam restorations are subjected to occlusal forces in service, both compressive and tensile stresses result in an amalgam restoration.
D	Tarnish is a surface reaction, and corrosion eventually causes the restoration to fail.

 

 

DIF:    Knowledge     REF:   p.  63             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

34. How will the mixture appear if amalgam is over-triturated?

a.	Puttylike consistency
b.	Dry, crumbly mix
c.	Wet, soupy mix
d.	Hard ball

 

 

ANS:  C

 

	Feedback
A	A is the result of proper trituration of the material.
B	B is the result of under-triturating the material.
C	Over-triturated amalgam is soupy and adheres to the inside of the capsule. It will have poorer strength and creep and may have poorer corrosion properties, all caused by over-formation of the matrix products.
D	Hard ball is the result of allowing the material to stand too long unused.

 

 

DIF:    Knowledge     REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

35. Which of the following are characteristics of under-triturated amalgam?

a.	Will appear dry and crumbly
b.	Does not condense well
c.	Is shiny in appearance
d.	A and B are correct.

 

 

ANS:  D

 

	Feedback
A	Under-triturated amalgam is dry and crumble in appearance.
B	Under-triturated amalgam is more difficult to condense.
C	Under-triturated amalgam has a dull, crumbly appearance.
D	A and B are correct.

 

 

DIF:    Knowledge     REF:   p.  66             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

36. Amalgam should be placed in the cavity preparation by _____________ increments.

a.	large to small
b.	consistent size
c.	small to large

 

 

ANS:  C

 

	Feedback
A	Large increments placed initially may leave voids in the mass.
B	Amalgam should be placed in small increments first to ensure proper condensation.
C	The assistant selects the end of the instrument appropriate for the clinical needs as directed by the operator; generally, smaller increments are used initially, graduating to larger increments.

 

 

DIF:    Knowledge     REF:   p.  67             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

37. What is the purpose of over-packing the preparation with amalgam?

a.	Adequate contour
b.	Correct occlusion
c.	Closed margins
d.	All of the above

 

 

ANS:  D

 

	Feedback
A	A, B, and C are all correct answers.
B	A, B, and C are all correct answers.
C	A, B, and C are all correct answers.
D	The cavity preparation is always over-packed with amalgam and carved back to final contours. Over-packing allows the practitioner to control the final shape and occlusion of the restoration more closely than would be possible otherwise.

 

 

DIF:    Knowledge     REF:   p.  67             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

38. Why is it important to use water when polishing an amalgam restoration?

a.	Assures integrity of the enamel
b.	Produces a high glossy finish
c.	So the tooth won’t overheat
d.	Insures smooth margins

 

 

ANS:  C

 

	Feedback
A	Enamel integrity is compromised by using highly abrasive materials.
B	A glossy finish is achieved by using abrasive polishes.
C	Polishing always should be done wet (with water), because dry polishing may overheat the amalgam and tooth. Overheating may damage the pulp of the tooth and the amalgam surface by driving mercury from the amalgam.
D	Margins are smoothed using abrasive stones or finishing burs to marginate the restoration.

 

 

DIF:    Knowledge     REF:   p.  68             OBJ:   6

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

39. Which of the following is a component of good mercury hygiene?

a.	Using a squeeze cloth to remove excess mercury
b.	Using premixed, sealed capsules
c.	Handling it only with gloves on
d.	Polishing using a dry technique

 

 

ANS:  B

 

	Feedback
A	Premeasured capsules eliminate the need to remove excess mercury.
B	The use of precapsulated amalgam limits handling of liquid mercury and reduces the possibility of a spill of liquid mercury in the office.
C	Mixed amalgam should never be touched, even with gloved hands.
D	Polishing should be done in a wet environment to reduce mercury vapor.

 

 

DIF:    Knowledge     REF:   p.  69             OBJ:   7

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

40. Which component added to silver alloy causes amalgam to expand if contaminated by saliva?

a.	Mercury
b.	Copper
c.	Zinc
d.	Tin

 

 

ANS:  C

 

	Feedback
A	Mercury does not cause the material to expand.
B	Copper does not cause the material to expand.
C	Historically, amalgams that contained zinc expanded sufficiently to fracture the tooth if they were contaminated with moisture during placement. The expansion occurred slowly over months after placement; restorations sometimes appeared to bulge out of the cavity preparation. Zinc is no longer used in silver alloy.
D	Tin does not cause the material to expand.

 

 

DIF:    Knowledge     REF:   p.  64             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

41. Of the following, which is an advantage of using spherical amalgam particles?

a.	Uses less mercury
b.	Easier to condense
c.	Sets slower for additional working time
d.	Produces a better interproximal contact

 

 

ANS:  A

 

	Feedback
A	Spherical alloy requires less mercury.
B	Irregular alloy is easier to condense.
C	Spherical alloy sets faster.
D	Spherical alloy provides a better interproximal contact.

 

 

DIF:    Comprehension                               REF:   p.  58              OBJ:   2

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

SHORT ANSWER

 

1. Compare and contrast corrosion and tarnish.

 

ANS:

Tarnish is a surface phenomenon that can result in a discolored restoration (Table 5-2). With tarnish, the chemical reaction between the amalgam and the oral cavity is restricted to the amalgam surface. Corrosion results from chemical reactions that penetrate into the body of the amalgam (Table 5-2). Although tarnish may be undesirable esthetically, it will not often cause a restoration to fail. Corrosion, on the other hand, eventually leads to failure of the restoration. Tarnish and corrosion occur more on amalgams with rough surfaces. Thus, a well-polished amalgam limits these problems.

 

DIF:    Knowledge     REF:   p.  65             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

2. Identify the three types of mercury and explain how each is acquired.

 

ANS:

Mercury occurs in three forms: elemental (Hg⁰), inorganic (Hg²⁺), and organic. Each of these forms has different dynamics of entry into and excretion from the body. Furthermore, we are exposed to the different forms from different sources. For example, the most common source of organic forms is fish. In general, the organic forms are the most toxic because they are most efficiently distributed to long-term storage sites in the nerve and fat tissues. Exposure to inorganic mercury is less critical because it is poorly absorbed.

 

DIF:    Knowledge     REF:   p.  69             OBJ:   8

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials

 

3. Compare and contrast expansion and contraction of a newly mixed amalgam.

 

ANS:

Ideally, a freshly mixed amalgam would neither expand nor contract as it sets after it is condensed into a cavity preparation. Expansion may result in post-placement sensitivity or even protrusion from the cavity, whereas contraction would leave gaps between the restoration and the tooth prone to leakage and recurrent decay.

 

DIF:    Knowledge     REF:   p.  63             OBJ:   5

TOP:   CDA, GC, III Chairside Dental Materials (Preparation, Manipulation, and Application) B, 1, Describe how to prepare, mix, deliver, and store restorative materials, including but not limited to a. amalgam

MSC:  NMDHE, 6.0 Providing Supportive Treatment Services, 6.1 Properties and manipulation of materials