A collagen-bone composition may include bone collagen and bone particles. The collagen may be in the form of a collagen suspension and the bone particles may be demineralized bone particles retained in collagen suspension. The composition may be prepared from pressure and thermal treatment of dry demineralized bone particles contacted with an aqueous medium to produce a viscous gel-like fluid. The fluid may include the collagen extracted from the demineralized bone particles. Addition of particulate bone may be used to increase the consistency of the composition, which may convert it into a paste or putty. The paste or putty may be suitable for ejection from a syringe. The collagen-bone composition may be preserved by freeze-drying or preferably by hypothermic dehydration. On reconstitution with aqueous medium, the preserved material may resume its original shape and properties.