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Dental Amalgam
Contributed by:
Andrea
SDH PRCC, MS.
- 2 or more metals or
combo of metals is known as an? Alloy
- What is a dental
amalgam? An alloy resulting when mercury is combined with silver, tin,
copper or zinc.
- The only metal
that’s liquid at room temperature is: Mercury.
- Can Mercury be
absorbed through restorations? No
- Mercury is very
toxic how can it be absorbed? Through direct contact with skin or it can
be inhaled.
- How should mercury
be stored (amalgam scrap)? In a capped jar with water & sulfur.
- Amalgamation is:
the forming of an alloy with Mercury.
- Low copper alloys
are bad in respect to physical properties.
- High copper alloys
are good in respect to physical properties.
- Why is shrinkage or
expansion not wanted in amalgams? Expansion causes Microleakage.
- Amalgams are
stronger in: compression.
- Over time what
happens to the strength of amalgams? The strength increases.
- Creep is the
gradual flow of material under: stress
- An increase in
creep value the amalgam is more likely to: fracture & have weak spots at
margins (marginal fracture).
- Mercury content in
amalgam? 50% or less.
- Tarnish: surface
discoloration.
- Corrode:
disintegration of surface, so strength affected.
- Polishing amalgams
will decrease what? Tarnish & corrosion.
- The mixing of an
alloy with mercury is done by: trituration.
- What controls the
quality of amalgam mass? Time, speed, & force.
- Force is the
function of: pestle.
- Pestle improves:
mixing.
- Steps in amalgam
prep:
- Trituration
- Carrier
-
Condenser/packer
- Carve
- Finish/
polish
- Moisture control is
important when placing amalgam because: moisture will cause a delayed
expansion.
- When is finishing
and polishing an amalgam usually done?
24 hours after placement.
- What should be
present when polishing? Water
- Under mixed amalgam
appears: dull crumbly.
- Over mixed amalgam
appears: soupy.
- The matrix bands
wider part is placed: coronally.
- What is the
function of a wedge? To prevent overhangs and allow for tight contacts.
- Undercuts=
mechanical retention.
- Finishing and
polishing amalgams can remove excess, but cannot correct: an under fill.
Disclaimer: These notes were
copied and pasted from files sent to me by Andrea. They have not been reviewed for errors. You are
responsible for checking out the information to verify the accuracy. This site,
Amy Nieves
and Andrea are not responsible for typographical errors.
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