Abstract The physical and mechanical properties of two photo-cured anterior filling materials and a photo-cured posterior filling material have been compared with those of a conventional-cure resin composite. The properties of these materials were found to be dependent on their matrix resin compositions, filler contents, and filler particle sizes. One material with a low (50%)inorganic filler content of small particle size (0.04 micron) was found to have a lower mechanical strength with significantly higher water sorption and solubility characteristics than more heavily filled materials. A new hybrid photo-cured anterior composite with a smaller filler particle size was found to have comparable sorption and solubility behavior but a tensile strength superior to that of a conventional-cure composite. The superior properties of the new photocured systems are thought to result from their hybrid composite structures and the smaller filler particle sizes.