Abstract: A combination dense/porous structure includes a porous element having an outer surface defining a shape having a bulk volume, the element includes a continuous framework having struts defining a plurality of interconnecting interstices throughout the bulk volume. The porous element has interconnecting interstices extending throughout the volume and opening through the surface. The combination dense/porous structure also includes a dense element formed from a material and having a sintered density of at least 95%, contacting at least a portion of the porous element; and an interconnection zone formed by the inter-penetration of the material forming the dense element into the porous element. The combination dense/porous structures are particularly useful as bone substitute materials and extended release delivery systems, preferable sustained release, for physiologically active agents.