Abstract
In order to compare the porosities of a spherical alloy amalgam and a conventional alloy amalgam, the ground sections of amalgam mixes and fillings condensed by varying techniques and pressures were examined. The conventional amalgam generally had little porosities in its mixes but had gross porosities along the junctions of increments in its fillings. Such porosities could be eliminated by efficient condensation. The spherical amalgam had many minute porosities in its mixes. The porosities along the junctions of increments were much less and smaller in its fillings but minute porosities distributed in the whole masses could not be eliminated even by the most efficient condensation.
