Amalgam
Metal alloy of which one of the elements is mercury
Alloys
Metals that are a combination of several elements
Dental amalgam
Made by mixing approximately equal parts of a powdered metal alloy with liquid Mercury
Amalgamation or trituration
The mixing process of the amalgam alloy with liquid Mercury
Amalgamator or triturator
Mechanical device that shakes the capsule containing the alloy and Mercury at high speed mixing the two components into a plastic mass
Working time
The time needed to to condense and carve
Mechanical retention
How is amalgam held in place?
Lathe cut alloys
Amalgam alloys made by grinding an ingot of metal
Spherical alloys
Amalgam alloys created by spraying molten metal into an inert atmosphere
Admixed, dispersioned or blended alloys
Products that are a combination of both lathe-cut and spherical particles
Amalgam alloy
Silver-tin powdered metal before it is mixed with Mercury
Dental amalgam
The result of mixing the powdered metal with Mercury and using it to restore teeth
Mercury
The only metal that is liquid at room temperature
Mercury combined with silver and tin
Composition of dental amalgam
Tough, wear resistant, long lasting, cost effective, seals margins
Advantages of dental amalgam
France in the 1800s
Initial development of dental amalgam
Dispersalloy
The first high copper amalgam
Gamma Ag-Sn phase
The strongest and most corrosion resistant phase
Gamma 1 Ag-Hg phase
Somewhat strong and corrosion resistant but brittle phase
Gamma 2 Sn-Hg phase
The weakest and most corrosion prone phase
Manufacturer and dentist
Factors affecting handling and performance of amalgam
Copal varnish
A resin dissolved in a solvent
Galvanic corrosion
Results when two dissimilar metals exist in a wet environment and an electric current flows between the two metals and corrosion of one of the metals occurs
Moisture
Causes a delayed expansion of amalgam
Nice, Smooth margins
Increases corrosion resistance
Matrix band and retainer
Required when placing a class II restoration
Small class One and class Five restorations
Where are direct gold restorations formally seen?
All surfaces of posterior teeth and occasionally lingual pits of anterior teeth
Where is amalgam used?
Precipitation
Process of a solid being formed from material dissolved in liquid
Tytin
The first single composition spherical dental amalgam
Tin and Mercury
Elements in the gamma two phase
Increase strength and corrosion resistance
Function of silver
The higher then strength and the lower the marginal breakdown
The lower the Mercury content
Copper
In high copper amalgam reaction, what does tin reacts with
Spherical amalgam
Softer, mushy amalgam
Over trituration
Results in amalgam looking crumbling, dry and already set
Class one, two, four and five caries
Does not pertain to the use of amalgam
0.1 percent
Patients that have a true Mercury allergy
Low strength
Why is gold foil limited to small restorations
Silver and tin
Elements of the gamma phase
Silver and Mercury
Elements of the gamma one phase