Deck 5: Dental Amalgam

Question 1

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

A) Silver
B) Copper
C) Tin
D) Mercury

Answer 1

Mercury

Question 2

An admixed dental amalgam contains _____ shaped alloy powder particles.

A) only irregularly
B) only spherically
C) a mixture of irregularly shaped and spherically
D) neither irregularly shaped nor spherically

Answer 2

a mixture of irregularly shaped and spherically

Question 3

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) Powder compressed into tablets and mixed with mercury in a reusable mixing capsule
C) Silver alloy powder and mercury sealed into a disposable hard plastic capsule
D) None of the above

Answer 3

Silver alloy powder and mercury sealed into a disposable hard plastic capsule

Question 4

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

A) Silver
B) Copper
C) Tin
D) Zinc
E) Mercury

Question 5

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.

Question 6

Which phase is absent in a high-copper amalgam?

A)
B)
C)
D)

Question 7

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

A) Beryllium
B) Sodium
C) Lead
D) Mercury
E) Gallium

Question 8

________ 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 vapor is released

Question 9

Under-triturated amalgam is:

A) soupy.
B) dull.
C) crumbly.
D) A and C.
E) B and C.

Question 10

The correct order for the manipulation of amalgam is:

A) carving, condensation, mixing, and finishing.
B) condensation, finishing, mixing, and carving.
C) mixing, condensation, carving, and finishing.
D) mixing, finishing, condensation, and carving.

Question 11

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

Question 12

The gamma-2 phase of amalgam is composed of:

A) silver-tin.
B) tin-mercury.
C) copper-tin.
D) silver-copper.

Question 13

Tarnish:

A) is a surface phenomenon.
B) is the result of chemical reactions that penetrate into the body of the amalgam.
C) is equivalent to corrosion.
D) eventually leads to failure of the restoration.

Question 14

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) 20

Question 15

Advantages of dental amalgam when contrasted with direct resin composite include all of the following except:

A) longevity.
B) superior esthetics.
C) ease of placement in diverse clinical situations.
D) marginal integrity in subgingival areas.

Question 16

High-copper amalgam has about _____ wt % copper.

A) 3
B) 5 to 10
C) 13 to 30
D) 30 to 40
E) 75

Question 17

Insufficient strength in a dental amalgam may lead to:

A) tarnish.
B) fracture.
C) condensation.
D) expansion.

Question 18

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

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

Question 19

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

A) Both statements are true.
B) Both statements are false.
C) The first statement is true; the second statement is false.
D) The first statement is false; the second statement is true.

Question 20

High-copper alloy amalgams have _____ than low-copper amalgams.

A) higher strength
B) less corrosion
C) better longevity
D) A, B, and C
E) A and C

Question 21

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 incorrect.
B) Statement 1 is correct; statement 2 is correct.
C) Statement 1 is incorrect; statement 2 is incorrect.
D) Statement 1 is incorrect; statement 2 is correct.

Question 22

Which of the following is not correct regarding admixed alloy?

A) It is a mixture of particles.
B) It is easy to condense.
C) It makes better proximal contacts.
D) It is easier to carve.

Question 23

Under-triturated amalgam:

A) will appear dry and crumbly.
B) is dull in appearance.
C) does not condense well.
D) all of the above.

Question 24

Which of the following is not correct regarding spherical alloy?

A) It sets faster than admixed amalgam.
B) It is easy to condense.
C) It makes better proximal contacts than admixed amalgam.
D) It requires more mercury than admixed amalgam.

Question 25

The purpose of over-packing the preparation with amalgam is to ensure:

A) adequate contour.
B) correct occlusion.
C) closed margins.
D) all of the above.

Question 26

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

Question 27

Amalgam should be placed in the cavity preparation by _____ increments.

A) large to small
B) consistent size
C) small to large

Question 28

On average,how much copper is in today's dental alloy?

A) 4%
B) 10%
C) 20%
D) 50%

Question 29

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.

Question 30

The most likely route of entry for mercury into the patient and dental personnel during the manipulation of amalgam is via:

A) contact through skin.
B) absorption in the gut.
C) the lungs as a vapor.
D) intraoral absorption.

Question 31

Using water when polishing an amalgam restoration will ensure:

A) a high glossy finish.
B) the tooth won't overheat.
C) integrity of the enamel.
D) smooth margins.

Question 32

Amalgam scrap should be:

A) disposed of in the trash with other daily refuse.
B) flushed down the drain with ample water.
C) stored in a sealed container in the refrigerator.
D) stored in a sealed container containing x-ray fixer or another reducing agent.
E) stored in a sealed container containing x-ray developer.

Question 33

Ultrasonic condensers are discouraged for condensation of amalgam because they:

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.

Question 34

Over-triturating an amalgam will result in a:

A) dry, crumbly mix.
B) puttylike consistency.
C) wet, soupy mix.
D) hard ball.

Question 35

High-volume evacuation should be used when _____ amalgam restorations.

A) placing.
B) polishing.
C) removing.
D) doing all of the above.

Question 36

Of the following statements about esthetic restorative materials,which is not correct?

A) Esthetic restorative materials have a longer longevity.
B) Esthetic restorative materials are more expensive.
C) There are placement challenges associated with esthetic restorative materials.
D) Esthetic restorative materials have a higher strength.

Question 37

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

A) Handling it only with gloves on
B) Using a squeeze cloth to remove excess mercury
C) Using premixed, sealed capsules
D) Polishing using a dry technique

Question 38

Today's dental amalgam:

A) is high in zinc.
B) is low in copper.
C) has high longevity.
D) has placement issues.