What is the difference between high copper and low copper amalgam?

Answer 1

Briefly explained, low copper amalgams are also known as "traditional" or "conventional" and have been used for many decades (even at present) and contain less than 6 % copper, while high copper amalgams contain more than 6 % copper, in fact there are 2 main groups, one containing around 12-13 % copper, and the other containing up to 30 % copper. The additional copper helps to increase the formation of gamma 1 (silver-tin) and prevent the formation of a weak phase of dental amalgams, named gamma-2 (tin-Mercury) and thus the strength of the final product is higher. Therefore, the high copper amalgams have a higher compressive strength and in general, better mechanical properties, but there is one disadvantage, they release more mercury vapor, a poison for the brain, CNS and many other cells.

Answer 2

High copper amalgams are a new class of amalgams introduced by manufacturers starting about 1975-1976. The high copper amalgams are called such because they contain a new mixture of metals that include a significantly higher copper content than the previous generation of amalgam.

The 'high copper' amalgams reportedly have better strength, durability and clinical outcomes than previous low copper versions.

Some amalgam critics have alleged that high copper amalgams off gas mercury vapor at a much higher rate than the previous low copper versions, up to 50x faster.