The invention provides:- A hydrophilic dehydrated partially purified bone replacement material of natural origin, wherein substantially all non-collagenous organic material is removed while inorganic, porous osseous structure and collagenous structure of natural bone are substantially preserved, characterized in that the bone replacement material contains 0.05 to 1.5 w/w % of a saccharide and/or a sugar alcohol, and 0.7 to 5.6 w/w % of a phosphate group which is apt to react with the calcium ions of physiological fluids to give a precursor of hydroxyapatite, this phosphate group being part of a physiologically acceptable salt,- a process for preparing a hydrophilic dehydrated partially purified bone replacement material, and- the use of 0.05 to 1.5 w/w % of a saccharide and/or a sugar alcohol to confer hydrophilic properties to a partially purified bone replacement material of natural origin, wherein substantially all non-collagenous organic material is removed while inorganic, porous osseous structure and collagenous structure of natural bone are substantially preserved..
