Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dental Materials 2 > Dental Amalgam > Flashcards

Dental Amalgam Flashcards

1
Q

what is dental amalgam a product of

A

amalgamation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is amalgamation

A

alloy + mercury react to form silvery hard grey mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what makes amalgam unappealing

A

poor aesthetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

why is dental amalgam use declining

A

development of viable alternatives

safety and enviro pollution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the two compositions of amalagam

A

conventional

high copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is x ray refraction used for

A

to work out crystal structure a scatters rays to work out distance between etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is most common composition of amalagam used today

A

conventional superseded by high cooper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what si the compositor of conventional

A 
65% Ag (min)
29% Sn (max)
6% Cu (max)
2% Zn (max) 
3% Hg (max)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what si the composition of high copper composition

A 
40% Ag (min)
32% Sn (max) 
30% Cu (max) 
2% Zn (max) 
3% Hg (max)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do variations of alloy morphology come about

A

lathe cut

spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a lathe

A

used to cut off bits of alloy into finer or coarse - changing how much in contact with mercury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is better about the high copper comp to the conventional

A

reaction changes gamma 2 slim and replaced

better corrosion resist and less susceptible to creep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the effector of a greater amount of Ag(3)Sn

A

undergoes setting reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what effect does copper have on amalgam

A

strengthening effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what does Zn act as in alloy production

A

scavenger which can complex with oxygen - leading to problems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what may be eliminated in an inert atmosphere

A

Zn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is mixing termed as

A

trituration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what are the dimensional changes take pace

A

30 mins - sell shrink

30-60 mins - expansion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

why at 30 mins is there a small shrinkage

A

Hg diffuses into alloy

20
Q

why at 30-60 mins expansion

A

due to crystallation

21
Q

what is the overall effect of size changes

A

net expansion/contraction

(+/-) 0.1%

22
Q

what does it mean hangs is given off

A

poor moisture control and Zn containing alloy - gas given off = greater expansion

23
Q

what is the tie of placement to function

A

15-20 mins

24
Q

when is final strength of malaga reached

A

24 hours

25
Q

what is compressive fore greater than

A

tensile and transverse

26
Q

when is madam weak

A

in this sections

27
Q

what is strength proportional of

A

Hg content

28
Q

what is the optimum of Hg

A

44-48%

29
Q

what si the creep prperty

A

plastic deformation under load

30
Q

what does the creep property clinically flow as

A

manifesting as protrusions at restoration margins

31
Q

what is ditching

A

fracture off of restoration margins

32
Q

what is largely responsible fro creep

A

gamma 2 largely responsible

33
Q

what does corrosion of allow exacerbates release

A

Hg in marginal crevice

localised expansion

34
Q

what is corrosion of amalgam

A

electrochem reaction of diff alloy phases with saliva as electrolyte
- gamma 2 anode

35
Q

what does gamma 2 do in corrosion of amalgam

A

breaks down to Sn and Hg

latter remains free and is ingested

36
Q

what do corrosion products provide

A

marginal seal

37
Q

in high copper phase what is undergoing most corrosion

A

Cu-Sn

38
Q

what does the metal of amalgam mean about thermal property

A

high thermal diffusivity

39
Q

what can Hg be toxic about

A

CNS

- signs and symptoms

40
Q

why are some linked condones with amalgam

A

multiple sclerosis

psychiatric distrnbace

41
Q

how to protect against enviro pollution go Hg

A

water of dental unit
release ofHg during titration
crematori

42
Q

what are somemanipulatve variables

A

alloy:Hg (5.8:10.8)

43
Q

how are drier mixes achieved

A

mechanical mixing

44
Q

what removes excess Hg

A

packing nd condensation

45
Q

what is dispensation

A 
weight
rarely used 
volume dispensers
alloy tablets
proportioning and mixing
46
Q

what is important about particle size of alloy

A

smaller achieves higher 1 and 24 strengths

if too small too rapid set

Dental Materials 2 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions