Amalgam Class I Preps Flashcards
Amalgam was the restorative material for the past ____ years.
150
What is the speed for the triturator?
upward from 3000 rpm
How long should you use the triturator?
5-20 seconds
What is the major element in amalgam?
silver
What are two major benefits of tin?
- reduces resistance to tarnish and corrosion
- increases the setting time
What is the main benefit of copper?
reduces the gamma-2 formation
What is the main benefit of zinc?
prevents corrosion and marginal breakdown
What is the main benefit of mercury?
makes the mixture pliable
What two elements are used in very small amounts in some compositions?
palladium and indium
What are the three different shapes of amalgam?
- lathe cut
- spherical
- admixed (both)
What are the four ways that amalgam changes over time?
- dimensional change
- strength
- corrosion
- creep
What is the dimensional change?
net contraction
How is strength different 1 hour after placement versus 24 hours after placement?
It’s stronger after 24 hours
What element in amalgam prevents creep?
copper
What happens when you over mix amalgam?
it gets sticky and decreases working/setting time
What are the three parts/types of burnishing?
- pre-carve
- post-carve
- combined
_____ removes excess mercury and improves margin adaptation.
Pre-carve
______ improves smoothness.
Post-carve
What is the benefit of combined burnishing?
less leakage
What uses a prophy cup with pumice, provides initial smoothness to restorations, and is recommended for spherical amalgams?
early finishing
