C11    Explain how microstructure, as well as manipulative variables, of amalgams will influence the creep properties of a set amalgam.

As mentioned before, the key difference between a low copper amalgam and a high copper amalgam is that the former forms a gamma-2 phase when it sets, while the latter a Cu₆Sn₅ phase. Of these two phases, the Cu₆Sn₅ phase is stronger and more corrosion resistant. In addition, when the Cu₆Sn₅ phase forms, it "pins" the gamma-1 crystals together, making it more difficult for the latter to slip. This explains the lower creep values of the high copper amalgams.

Manipulative variables that affect the mercury content also affect the creep value. Thus, more residual mercury results in higher creep values. More residual mercury relates to less efficient condensation or use of more mercury retaining alloy particles (e.g. lathe-cut particles or smaller particles). Overtrituration can also result in that alloy particles (particularly lathe-cut particles) fracture into smaller particles. The formation of smaller particles increases the total surface area, which in turn will retain more mercury and form an amalgam that has higher creep than one from which more mercury could be removed during condensation.