A

Because the smooth, round particles of spherical high-copper amalgam move past one another readily, they compact at an adequate density with much lower hand-condensation pressure than the irregular, lathe-cut particles that interlock and resist packing. Experimental work shows spherical alloys are “comparatively insensitive to condensation pressure,” whereas lathe-cut and admixed alloys need markedly higher forces for optimal properties [Brown, 1993, PMID 7880469].