**Amalgam

Question 1

Define amalgamation

Answer 1

the reaction between alloys and mercury to make amalgam

Question 1

Define alloy

Answer 1

a mixture of metallic elements

Question 2

Define trituration

Answer 2

the mixing of the mercury and alloy powder in the amalgam capsule

Question 3

Define creep

Answer 3

the slow change in dimensions of the amalgam due to prolonged exposure to stress

Question 4

What occurs when amalgam slowly moves out over the cavosurface margins under occlusal pressures?

Answer 4

creep

Question 5

Define corrosion

Answer 5

the process where metal is eaten away by a chemical reaction

Question 6

Is corrosion due to a chemical or mechanical reaction?

Answer 6

chemical

Question 7

Define galvanism

Answer 7

an electric current created by a chemical reaction of dissimilar metals

Question 8

Define tarnish

Answer 8

the discoloration of the surface of the amalgam

Question 9

List the four major types of alloy in amalgam

Answer 9

silver, copper, tin, and zinc

Question 10

What type of metal is the highest percentage of the alloy?

Answer 10

Silver

Question 11

What type of metal is the lowest percentage of the alloy?

Answer 11

zinc

Question 12

What type of metal in the alloy is used to prevent oxidation during the manufacturing process?

Answer 12

zinc

Question 13

What type of metal in the alloy forms a metallic compound with the mercury?

Answer 13

silver

Question 14

List the three types of of size/shapes of the alloy particles in amalgam?

Answer 14

Lathe-cut, spherical-cut, mixture of cuts

Question 15

What type of alloy particle cut requires the least amount of mercury?

Answer 15

spherical-cut

Question 16

Amalgams with ____ mercury content generally have better properties.

(low or high)

Answer 16

low

Question 17

How is mercury absorbs into the human body?

Answer 17

Through the pores in skin or by inhalation

Question 18

Approximately what percent of mercury is left in a finished amalgam restoration?

Answer 18

3%

Question 19

During placement of the amalgam restoration, what process allows the mercury-rich layer to rise to the surface and be removed?

Answer 19

Condensing

Question 20

Is a higher or lower ratio of mercury a quicker setting time?

Answer 20

Lower

Question 21

What percentage of mercury ratio is considered a “mercury-rich” amalgam?

Answer 21

More than 54%

Question 22

What causes the Gamma 2 phase?

Answer 22

inadequate condensation of amalgam during placement of the restoration

Question 23

What metal in an alloy can help reduce problems with the Gamma 2 phase?

Answer 23

high amounts of copper

Question 24

The Gamma 2 phase of a combination of what two materials in amalgam that decreases the strength of the final restoration?

Answer 24

tin and mercury

Question 25

What is inside each amalgam capsule?

Answer 25

a pre-measured amount of alloy and mercury

Question 26

Define pestle

Answer 26

a metal or plastic piece placed inside the amalgam capsule to aid in the mixing process

Question 27

What is a spill of amalgam?

Answer 27

the amount of material inside each amalgam capsule

Question 28

The settings on the amalgamator that determine the quality of the amalgam capsule's mixture includes what?

Answer 28

mixing time, speed, force

Question 29

How will an overtriturated mix appear?

Answer 29

crumbly and dull

Question 30

How will an undertriturated mix appear?

Answer 30

soupy

Question 31

Where are amalgam scraps stored?

Answer 31

Regulated waste amalgam containers

Question 32

Define burnishing

Answer 32

the process of using a ball burnisher instrument to lightly rub over the surface of the amalgam restoration to smooth it and achieve a dull luster (optional procedure)

Question 33

When an amalgam restoration is successfully burnished, how will it appear?

Answer 33

smooth, dull luster

Question 34

Define: flash

Answer 34

excess

Question 35

Define: overhang

Answer 35

excess restorative material that has leaked under and out of the matrix band

Question 36

Define: open margins

Answer 36

a space left between a tooth and the restorative material due to inadequate condensing of the material

Question 37

Define: ditching

Answer 37

creation of scratches or concave areas due to excessive finishing of the amalgam

Question 38

In a Class 2 restoration, it is indicated to place the first increment of amalgam in the least accessible area of the prep. Where would this be?

Answer 38

the proximal box

Question 39

When carving anatomy in an amalgam restoration, what type of motion will you use to activate the instrument?

Answer 39

pulling motion

Question 40

How long after placing an amalgam restoration should you wait to finish and polish the restoration, if needed?

Answer 40

24-48 hours, per manufacturer's instructions

Question 41

Why can amalgam not be finished/polished the same day as the restoration is placed?

Answer 41

premature finishing and polishing will disturb the crystalline structure of the hardened amalgam, and will weaken the restoration