The preparation of dental restorative polymeric materials was carried out using freeze-dried silica filler which surface was treated with silane to improve the miscibility with matrix resin. DTS of the microfilled dental composites was measured and the effect of drying procedure on DTS values was also investigated. Materials prepared by using freeze-drying method showed higher DTS values than that of conventional heat-drying one. With increasing the loading percentage of filler onto resin. DTS values was dramatically increased. It was also examined the dispersity of inorganic filler into Bis-GMA matrix and surface characteristics by scanning electron microscopy.