DESCRIPTION: In Phase I, Ultramet demonstrated the fabrication of open- cell tantalum foam as a potential bone implant material. Tantalum has a long history of use as a biomaterial, and the lightweight, strong, porous foam structure closely mimics the microstructure of natural bone. Fabrication, mechanical and corrosion studies were positive. Preliminary implantation studies in goats and dogs have shown outstanding bone growth, excellent biocompatibility and interfacial strengths. The objective of Phase II is to perform a validation study to develop an optimized repeatable, fully characterized tantalum foam material and fabrication process. This work should lead to the submission of an IDE in various areas. Previous studies were non load bearing. The proposed studies will be placed in dynamic, load bearing sites in a canine mandibular defect.