Time dependent polymerization on microfilled and small particle dental composites

There have been previous reports of time dependent property changes in composite resins. However, the changes in material properties have not been correlated to the ratio of resin matrix/filler contents and composite morphology in previous reports. The objective of this investigation was to characterize the Vicker's hardness changes in two dental composite resins with defined differences in the resin matrix to filler weight ratios as well as particulate size differences.