A bone graft material is provided comprising granules of synthetic bone material, at least some of which have a solid coating comprising a blood-clotting agent. A device for delivering bone-replacement material to a an area to be treated is also provided, the device comprising: a chamber for containing bone-replacement material, wherein the chamber is pre-loaded and/or pre-coated on an interior surface thereof with a blood-clotting agent； means for introducing bone-replacement material into the chamber to contact the blood-clotting agent； and a means for delivering the bone-substitute material from the chamber to the area to be treated.
