Dm Direct Filling Gold

Front 1

Gold is the most _______, ______, and ______ metal.

Back 1

noble, malleable, ductile

Front 2

Gold is used in dentistry as ___________ or ____________.

Back 2

cast gold or direct filling gold

Front 3

Direct filling gold is used to restore small Class ___, Class ____ and Class _____ cavities

Back 3

Class I (usually premolars), Class III, Class V

Front 4

(T or F) Direct filling gold is recommended for use in esthetic, high stress bearing areas.

Back 4

False. Recommended for NON-esthetic, LOW stress bearing areas. (That is unless you are thinking of dropping out of dental school and becoming a rapper wit yo new grill.)

Front 5

Compaction raises the strength of gold how?

Back 5

by strain-hardening (work-hardening)

Front 6

Gold is chemically (active/inactive) and (affected/unaffected) by air, moisture, heat, and most solvents

Back 6

chemically INACTIVE and NOT AFFECTED by all three (air, moisture, heat and most solvents)

Front 7

(T or F) Gold can be cold-welded at room temperature.

Back 7

True. Due to presence of metallic bonds

Front 8

Gold has (high/low) thermal conductivity and (high/low) density.

Back 8

HIGH thermal conductivity
HIGH density (19.3 g/cm^3)

Front 9

List the forms of direct filling gold.

Back 9

Preformed gold foil
Electrolytic precipitate
Powdered gold

Front 10

Why is it difficult to form a dense restoration with Gold?

Back 10

Because of its very high density (19.3 g/cm^3)

Front 11

Example(s) of preformed gold foil include:

Back 11

gold leaf and fibrous gold
(can be made into sheets, ropes, cylinders, laminated foil, or platinized foil)

Front 12

Example(s) of electrolytic precipitate include:

Back 12

mat gold and crystalline gold

Front 13

Example(s) of powdered gold include:

Back 13

granular gold

Front 14

Au-Ca alloy is an example of what form of direct filling gold?

Back 14

electrolytic precipitate

Front 15

All types of direct gold are 99.99% pure except for ..............?

Back 15

platinized foil and Au-Ca electrolytic precipitate (contains 0.1% Ca)

Front 16

Electrolytic and powdered gold are made from No. ___ foil, whereas corrugated No. ___ is rolled into ropes and cylinders.

Back 16

No. 3
No. 4

Front 17

Cylinders can be formed from No. ___, ___, or ___ foil.

Back 17

4, 60, 90

Front 18

Preformed gold foil is generally used (on the surface of/within) the restoration.

Back 18

on the surface of

Front 19

Name the preformed gold foil that is made by hammering Pt foil between two layers of No. 4 gold foil

Back 19

Platinized foil

Front 20

What is another way to make platinized foil OTHER THAN hammering Pt foil btwn 2 layers of No. 4 gold foil?

Back 20

by cladding: bonding layers of Au and Pt together

Front 21

Why is Pt added to Au?

Back 21

Pt increases hardness and wear resistance of Au foil

Front 22

What is cohesive foil?

Back 22

Au foil that is free of contaminants

Front 23

Gold foil that is treated with a volatile protective agent to keep other impurities from forming on the gold and to prevent premature cohesion is called what?

Back 23

noncohesive foil (go figure)

Front 24

What is an example of the volatile protective agent used when creating noncohesive foil?

Back 24

ammonia

Front 25

Upon making a noncohesive foil, how is the volatile film removed?

Back 25

by heating the foil (to restore the cohesive nature of the foil)

Front 26

What is another name for degassing desorption?

Back 26

Heat treatment

Front 27

During degassing desorption, heating is accomplished over an open flame of ____ ____ or on an annealing plate from ____ - ____ degrees C.

Back 27

pure alcohol
650 -700

Front 28

Electrolytic precipitate is a powder formed by electrolytic precipitation, shaped how?

Back 28

By sintering below the melting point of Au (1, 063 C)

Front 29

(T or F) Mat gold can be used on the surface of a restoration.

Back 29

FALSE. Because mat gold is loosely packed, friable, and contains voids

Front 30

What does the 0.1% of Ca contribute as a component of Au-Ca electrolytic precipitate?

Back 30

It results in dispersion strengthening

Front 31

Electrolytic precipitate has (atypical/typical) dendritic structure with crystals ___ mm long.

Back 31

TYPICAL
0.1 mm

Front 32

Mat foil = sandwich of ______ + _______

Back 32

Mat gold
No. 3 foil in strips

Front 33

Loose powder disintegrates when compacted, so the powdered gold is mixed with ____ to shape the pellet and then a covering of ____ is used.

Back 33

WAX
FOIL

Front 34

What must be eliminated from powdered gold before use?

Back 34

wax bonder

Front 35

Powdered gold is made by enclosing ______ or ______ ______ Au powder in No. ___ gold foil.

Back 35

ATOMIZED
CHEMICALLY PRECIPITATED
NO. 3 GOLD FOIL

Front 36

Powdered gold is made in such a way to form (regularly/irregularly) shaped, (precondensed/postcondensed) pellets.

Back 36

IRREGULARLY
PRECONDENSED

Front 37

What is essential to ensure a cohesive mass?

Back 37

Decontamination of desorption

Front 38

Decontamination by desorption is essential to maximize the ____ _____ of the restoration.

Back 38

Physical properties

Front 39

Strength and hardness of compacted gold vary depending upon what?

Back 39

Type of gold used and the method of compaction (hand and/or mechanical)

Front 40

(T or F) Properly condensed gold foil is harder than softened Type I cast gold alloy.

Back 40

TRUE