Partial Denture Alloys Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

what are the ideal properties of a partial denture alloy?

A
  • rigid
  • strong
  • hard
  • ductile
  • precise casting
  • low density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the most common partial denture alloys used ?

A
  • cobalt chromium

- type IV gold

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

for a partial denture alloy base what is the ideal YM and EL?

A

High YM = to maintain shape in use

High EL = to avoid plastic deformation

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

in a partial denture alloy clasp what is the ideal YM and EL values?

A

Lower YM = to allow flexure over tooth

High EL = maintain elasticity over a wide range of movement

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

what type of cavities can pure gold be used for?

A
  • Class III

- Class IV

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

what occurs to the melting point of gold alloys if copper is the alloying element?

A

reduced melting point

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

how does alloying with copper affect the density of gold?

A

reduced density

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

what may occur to gold alloys if too much copper is added?

A

corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is an alloy used that is similar to platinum?

A

palladium (less expensive)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are some uses for CoCr?

A
  • cast partial dentures
  • wires
  • surgical implants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

for CoCr partial denture connectors, explain the desirable EL & YM for the palatal/bulky section of connector?

A
  • high EL

- high YM

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

if CoCr is being used in partial denture clasps, explain the desirable EL & YM?

A
  • high EL

- low YM

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

what is the composition of CoCr?

A
  • Co (54%)
  • Cr (25%)
  • Ni (15%)
  • Mo (5%)
  • C (0.4%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is a positive reason to use Cobalt in alloys?

A
  • increased strength, hardness, rigidity

- coring is possible

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

in CoCr, what is the function of the chromium?

A
  • increased strength, hardness, rigidity
  • coring possible
  • corrosion resistance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does chromium in CoCr allow for corrosion resistance?

A

forms a passive layer on the surface of the alloy

17
Q

what is the purpose of addition of Nickel to CoCr (used in partial dentures)? what is a negative of using this also?

A
  • improves ductility

- slight reduction in strength & people may be sensitive/allergic

18
Q

what are the different casting techniques used for CoCr?

A
  • investment material
  • melting
  • casting
19
Q

how hard is CoCr?

A

BHN 370

20
Q

what are some positive reasons to use titanium in partial dentures?

A
  • good biocompatibility
  • good corrosion resistance
  • parts can be joined by laser welding
21
Q

what is a disadvantage of using gold in partial dentures compared to cobalt chromium?

A

gold is much denser (less comfortable)

22
Q

what is an advantage of using gold for RPD clasps over cobalt chromium?

A

gold is less rigid & can therefor flex into undercuts easier