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60 Cards in this Set

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The following alloys are considered (HN/N/PB) alloys:

Fe-Cr
Co-Cr
Ni-Cr
Ni-Cr-Be
Ni-Co-Cr
Ti-6Al-4V
Ti-6Al-Nb
Predominantly Base Metal (PB)
Ti is a base metal ___ and not an alloy
element
CP Ti stands for ____
commercially pure Ti (Titanium)
Ti is the (most/least) biocompatible metal
most
Ti is used to fabricate what 4 types of dental restorations?
all-metal
metal-ceramic
implants
RPD framework
CP Ti is available in how many grades?
5
The 5 grades of CP Ti are based in the concentrations of ___ and ___
O2 and Fe
What is the range of O2 for CP Ti?
0.18-0.40 wt%
What is the range of Fe for CP Ti?
0.2-0.5 wt%
What three elements, other than Oxygen and Iron are also present in CP Ti?
N2, C, H2
What are the wt% of N, C and H2 in CP Ti?
N = 0.03-0.05
C = 0.1
H2 = 0.02
Grade __ is the purest and softest CP Ti
1
What are the 5 grade numbers of CP Ti?
1, 2, 3, 4, 7
Ti has (high/low) MP and (high/low) hardness
high, high
True or false, Ti requires special arc-melting equipment
True
Ti is (very/not very) resistant to sag formation and has a (high/low) CTE
very, low
Ti alloys have properties (better/worse) than CP Ti and slowly release what two elements?
better, Al, V
What is the term for the formation of protective film on the surface of a metal by a reactive element?
passivation
passivation is the formation of a protective film on the surface of a metal by a ___ element
reactive
What are three examples of "reactive elements" in passivation?
Ti, Al, Cr
PR alloys containing > or = to __ wt% Cr form a NONporous layer of Cr2O3 on the surfaces (before/after) exposure to atmospheric O2
12, after
In passivation, the oxide forms a (pore/barrier) to the flow of O2 and metal ions, preventing further oxidation and protection from corrosion
barrier
Modulus of elasticity is important in ___ ___ alloys because it determines how thick the different parts of the framework must be to resist ____
denture alloys, deflection
PB alloys, except __, are (2/4/10) times as rigid as type IV gold
Ti, 2
True or false, PB alloys can afford more resistance than the same thickness of Type IV gold
True
What happens to the modulus of elasticity of an alloy AFTER heat treatment?
Nothing! It's only slightly affected... known as "structure-insensitive"
PB alloys:

1. (harder/softer) than HN and N
2. (weaker/stronger) than HN and N
3. have (low/high) hardness

Note: The exception to 1 and 2 would be Ti
harder, stronger, high
PB alloys are (easy/hard) to polish. Why?
hard, they have high hardness
True or False, PB alloys can be hardened further by heat treatment
False! This does not work!
If Type IV gold is heat treated, it can become harder, up to __% less hardness than PB
30
PB alloys have (low/high) elongation values which makes them (hard/easy) to burnish
low, hard
which has a HIGHER specific gravity, Gold or PB?
Gold
HN alloys are how much denser than PB?
twice

HN = 18.4g/cm^3
PB = 8.0 g/cm^3
If you were going to make the same casting from HN and PB, which would require a larger amount of material by weight?
HN
HN and N are how much more expensive (per oz) than PB?
thirty or more times as costly (wow...)
(HN/N/PB) have high MP and require special treatment, investment, and finishing
PB
Cost of an alloys is usually presented as cost/____
volume
To calculate cost of an alloy, you must include the ___ and price per ounce
density
The difference in cost of a HN and PB alloy can amount to a factor of __ (#)
80
True or false, in calculating cost comparison, density is irrelevant as long as you know the cost/ounce
False! you need density!
ADA spec # __ limits the content of what element to only 2% in PB alloys?
14, Be (Beryllium)
Why is Be included in No-Cr alloys?
improves the quality of the oxide layer
The oxide layer is essential for bond formation to what material?
porcelain
Be in Ni-Cr enhances the castability of the alloy in concentrations < or = to __ wt%
1.8
Which can be casted into more intricate designs and finer detail, PB or Au alloys?
PB
What metal is considered the more biocompatible of all metals?
Ti
What two metals do some PB alloys contain that are considered potential allergens? (Hint: NOT in HN or N)
Ni and Be
Allergy to ___ (metal) is the most commonly encountered metal allergen and should be avoided for patients with known __-contact hypersensitivity
Nickel, Ni
Who is most at risk to the carcinogenic effects of Ni?

patients
dentist
dental techs
hygienists
assistants
dental techs (exposure to Ni dust)
What is the OSHA limit for Ni? (concentration/hour)
15 micrograms/m^3 for a 10 hour exposure
Some Ni-Cr contain __ to reduce fusion temp, improve casting, and refine grain structure
Be
Be has been shown to cause a chronic, inflammatory disease of the ___ known as berylliosis
lung
True or False, the body excretes Be within 1 week
False, according to the lecture notes, the body CANNOT excrete it
The presence of Be dust may be encountered after __ or ___ (procedures)
melting, grinding
Be alloys with < or = to 3% Be are tolerated to what extent compared to alloys without it?
About the same
True or false, Be containing alloys have proven to have devastating long term effects in dentists and patients, even at concentrations <3%
False, no risk as long as proper ventilation is maintained in the operatory
When working with Be containing alloys, the dentist needs to insure that ___ is close by

cotton products
HVE
Dixie, your assistant
A gumby
A herd of honey badgers
HVE
What is the OSHA limit for Be? (concentration/time)
2 micrograms/m^3 for an 8-hour exposure
List the 3 alloys currently used at OUCOD... good luck...
1. Argebond 80 (N alloy) for MCR
2. Argenco 58 (HN alloy) for all-metal restorations
3. Argenco 42 (N alloy) for cast dowels
List 5 alternative technologies to cast metal technology
metal foil
CAD/CAM
Copy milling
electroforming
new technologies