Copper Enriched Amalgam

Question 1

What are alternative names for copper enriched amalgam

Answer 1

Non-y2 or high copper amalgam (must be at least over 6%)

Question 2

What are the properties of copper enriched amalgam

Answer 2

Strength
Abrasion resistance
Creep
Thermal expansion
Setting shrinkage

Question 3

What are the different types of copper enriched amalgam

Answer 3

Dispersion modified - original type

Single composition types - different setting reaction

Question 4

Describe dispersion modified amalgam

Answer 4

Originally Ag-Cu spheres and conventional lathe-cut alloys
It was expected that Ag-Cu would increase amalgams mechanical strength
Cu added beneficial modifications to the setting reaction

Question 5

What are the benefits of copper enriched amalgam

Answer 5

Stronger at early stages and in longer term
Less creep
Higher corrosion resistance
Less likely to fracture around the margins - increased durability of margins

Question 6

Describe the dispersion modified setting reaction

Answer 6

First stage is the conventional setting reaction
In the second stage y2 reacts to AgCu particles, producing CuSn and more y1 phase
This takes days to complete

Question 7

Describe single composition copper enriched amalgam

Answer 7

Cu is integrated into the AgSn alloy particles - hence Ag-Sn-Cu powder is mixed with Hg liquid
Typically between 12-30% copper
Particles can be lathe-cut or sphere

Question 8

Describe the setting reaction products of single composition amalgam

Answer 8

Products include unreacted AgSnCu particles which are encapsulated by the y1 phase
No y2 phase is produced, instead CuSn particles are produced