Described are osteogenic implants that include a first implant material covered at least in part by a second implant material carrying an osteogenic protein such as a bone morphogenic protein. The first implant material can comprise a mineral and provide an inner scaffolding portion for supporting bone ingrowth, and the second implant material can comprise a collagen or other sponge carrier covering the first implant material and having a liquid osteogenic protein formulation imbibed therein. Related implant materials and methods of preparation and use constitute additional aspects of the invention.