Brainscape's Knowledge GenomeTM

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


See full index

Biomaterials > metals > Flashcards

metals Flashcards

1
Q

noble metal

A

metals with minimla chemical reactivity

  • resits oxidation, corrosion, tarnsih
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

precious metal

A

have intrinsic value, noble +silver

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

base/ non-precious metal

A

inexpensive non noble metals

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

Pt stands for

A

platinum (platinum group of noble)

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

Pd stands for

A

Palladium (platinum group of noble)

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

Ir stands for

A

Iridium (platinum group of noble)

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

Rh stands for

A

Rhodium (platinum group of noble)

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

Os stands for

A

Osmium (platinum group of noble)(platinum group of noble)

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

Ru stands for

A

Ruthenium (platinum group of noble)

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

Au stands for

A

Gold

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

characteristics of gold

A

soft, malleable, primary compoennt of alloys

resistant to oxidation / corrosion

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

gold in contact with what causes problem?

A

maybe next to amalgam

- current set up and get mercury release

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

carat and fineness of gold

100% =
75%

A

24K = 100% - 1000 fine

18K = 18/24=75% Au = 75 fine

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

Tm of gold

A

1063 degrees celcius

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

effects of adding platinum

A 
tough, ductile, malleable, alloy with gold to INCREASE HARDNESS AND STRENGTH 
improve color (its silver) 
Tm = 1755
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

palladium addition?

A

similar to platinum
- substituted for pt in alloys to increase strength
silver alloy inhibits corrosion and absorbs H during casting

Tm = 1555

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

iridium and ruthenium addition?

A

GRAIN REFINERS

  • 0.0005%
  • SMALLER CRYSTALS AND HIGHER CRYSTAL CONTENT –> IMPROVED MECHANICAL PROPERTIES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Rhodium addition?

A

allow with pt- thermocouples

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

what type of metal is silver
abbreviation?
highest/best what?
reactive with?

A

Ag - precious metal
- malleable, ductile, best electrical and thermal conductor

very reactive with sulfur, chlorine, and phosphorus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

silver often in combination with?

A

Palladium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

base metal that is used a lot?

A

copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Cu is?

A

Copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

charactersitics of copper

A

good thermal/ electrical conductor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cu-Zn alloy is?

A

Brass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

copper and gold form

A

different crystal structures
- depending on treatment of the casting (like heat treating) can adjust the properties

HEAT HARDENING / SOFTENING WITH THIS

SO SOLID SOLUTION WITH AU

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

PHASE OF AU-CU IS DEPENDENT ON? what are they

A

the temperature
1. solid solution - when >424 (above) degrees celcius

  1. intermetallic ordered phase
    when <424
    AuCu3

ALTERS MECHANICAL PROPERTIES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

solid solution of Au and Cu

A

random orientation

material that is more flexible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

ordered phase of Au and Cu

A

material is stronger and less flexible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

SOLID SOLUTION ARRANGEMENT

A

more random

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

intermetallic compoiunf alloy

A

secific composition
- single phase

stronger but more brittle

31
Q

heat treatment to soften?

A

QUENCH in water immediatley

700 celcius for 10 minutes

32
Q

heat treatment to harden

A

450 celcius for 2 minutes

cool to 250 celcius in 30 minutes

33
Q

if want to seal margins? want to amke something stiffer

A

quench, cast , throw in water

cool and then put into water

34
Q

heat treatment effect on hardening

A
  1. increased tensile strength
  2. increased yield strength
  3. increased hardness
  4. decreased elongation
35
Q

Type I -IV detnal gold casting

properties as go from I-IV

A

Au content decreases from I-IV

  • harndess increases
  • strenght increaeses
  • mechnical properties increase
  • Cu content increases
  • can increase size of restoration usually
  • metling range decreases
  • changing mechanical properties
36
Q

best mechanical properties in what type of alloy?

A

Type IV

goes up from type I - to type IV

IV – brdiges and partial denture framework

37
Q

Type I can be used for restoring?

A

Class III and V

- small restorations

38
Q

Type II can be used for restoring?

A

medium harness, inlays

39
Q

Type III can be used for restoring?

A

inlays onlays crowns bridges

40
Q

Type IV can be used for restoring?

A

crowns, bridges, partial denture framework

41
Q

ability tomburnish harden as go from type I to type IV

A 
decreases 
I -- maximal
II- yes 
III- some
IV - minimal
42
Q

ability to heat harden from type I to type IV?

A 
increases 
I- none 
II- minimal 
III - moderate
IV - maximal (50%)
43
Q

long spanding bridge impliciation

A

more deformation that is likely to occur

so increase the elastic modulus to decrease the deformation

44
Q

T/F you can heat harden to increase the elastic modulus?

A

YES – so consider doing this for a bridge framework

45
Q

Bridges take into account what law?
stress =?
deformation=?

A

Law of beams
stress = 3x load x length /2x width x thickness

deformation = loadx length / 4x elastic modulus x width x thickness

46
Q

low noble metal alloys used for?

A

PFMs

Type A, B, and C

47
Q

general properties of low noble metal allows of type A, B, and C

A
  1. higher mechanicla properties than type IV
  2. low elongation
  3. high hardness
  4. high strenght

Type C has lowest yield strength

48
Q

are low noble metal allows burnishable? resitant to corrosion?

A

not burnishible but corrosion resistant

49
Q
  • quenching a casting in water versus slow cooling
A

quench = malleable – like sealing the margins

slow cool = harden –> resist deformation like in bridges

50
Q

can you seal the margins / want to seal the margins?

A

ask lab to quench it

51
Q

when / why harden a casting?

A

bridge

52
Q

type what for bridge? wtype for inlay?

A

type III / IV - bridge

inlay I (small) or type II

53
Q

globing warming is caused by

A

lack of pirates

54
Q

Types of alloys for metal-ceramic restorations

A

type 1-6 alloys
noble metal allloys 1-3

non-noble types 4-6

55
Q

mechanical properties and usual makeup of noble metal ceramic alloys

A

usually gold, platinum, palladium,

easy to work with, adjust, and nice bonds formed

56
Q

*what is used to bond the surface of the metal to the porcelain/ ceramic?

A

oxide layer – by adding alloys

added indian or tin

57
Q

type 4-6

A

base metals
type 4 - Ni-Cr
type 5 - Co- Cr
Type 6 - titanium alloy

58
Q

base metals usually create what type of oxide layer?

A

thick - so resoration may be hard to look esthetics

can create problems with fracture if too thick

59
Q

importance of In or Sn

A

noble- metal- ceramic alloys and are primarily added to improve the bonding to the porcelain by creating an oxide layer

60
Q

Pt and Pd with effect with noble metal - ceramic alloys

A

increase mechanical properties

- alter the thermal expansion coefficient and increase melting range

61
Q

T/F base metals are difficult to cast

A

true

62
Q

*True or false base metal- ceramic alloys may contain Ni

A

TRUE

- allergies to the base metals

63
Q

reason for porcelain de-bonding with base metal ceramic alloys

A

oxide bonding layer too think

also leads to poor estehtics due to dark oxide layer on the metal

64
Q

what are base metals used for?

A

PFM’s

65
Q

Composition of base metal alloys

A

cast cobalt - chromium- nickel alloys

Minimum 85% Co Cr and Ni

minimum 20% Cr

66
Q

yield strenght of base metals

A

500 MPa

67
Q

what is major use of cromium in base metals

A

prevent corrosion

68
Q

uses of Co-Cr-Ni

A

removable partial denture framework

crown and bridge

bone plates, screws

69
Q

implication of nickel

A

allergies!

70
Q

do vitallium and nobillium have nickel?

A

no

71
Q

does ticonium have nickel

A

yes (no Co)

this is a lot!

72
Q

what happens if there is too much carbon?

A

the framework can become too brittle and break more easily

73
Q

*RPD alloys commonly used?

A
  1. Vitallium
  2. Ticonium (contains Ni!!)
  3. Nobilium

Biomaterials (16 decks)

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