The success of orthopaedic implants fixed in the skeletal system using bone ingrowth into porous surfaces is critically dependent on the extent and quality of the initial bone ingrowth and the subsequent long-term maintenance of the bone within the porous structure. Biologically-significant elements (Ca, Mg, Mn) were incorporated at concentrations up to 5 mol% in solid solution in yttia-stabilised tetragonal zirconia polycrystal (3YTZP), whilst controlling microstructure and phase composition, to investigate the effect of ceramic chemistry on cellular behaviour in vitro and bone ingrowth into porous structures in vivo. Cellular attachment, proliferation, and migration on the ceramics were investigated using in vitro assays using fibroblasts. Cells were able to adhere strongly and proliferate on all ceramic surfaces, exhibiting maximal proliferation and minimal migration on 3YTZP but significantly faster migration on doped-3YTZP. The TZP ceramics were therefore considered to support normal cellular processes and thus were suitable for further study in vivo. A technique based on pressure casting ceramic slurry into a polymer preform of the desire pore structure, followed by polymer burnout and then sintering, was developed for fabricating porous bioceramics containing highly-controlled three-dimensional pore geometries. The ability of a selected pore structure to support bone ingrowth was tested using hydroxyapatite by implanting samples into femoral cortical bone of adult sheep for 4 and 12 weeks. Bone was able to rapidly colonise the porous structure and remodel such that, by 12 weeks implantation time, the majority of the porosity was filled with mature lamellar bone. Porous scaffolds of pure 3YTZP and 3YTZP doped with 1 mol% Mg, 1 mol% Mn, 1 mol% Ca, or 5 mol% Ca were fabricated and tested in the sheep model. Bone ingrowth into the doped compositions was significantly greater than that into pure 3YTZP, and was similar to that into the porous hydroxyapatite, indicating that the dopants significantly promoted osteogenesis within the bioinert scaffolds. This finding has application in clinical applications in that the initial bone ingrowth and, potentially, the long-term maintenance of bone within the porous structure may be improved by the incorporation of small amounts of biologically significant elements.

Thesis (M.S.)--Ohio University, June, 1988. / Title from PDF t.p.

Thesis (M.S.)--University of Missouri--Rolla, 2002. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 25, 2008) Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 84-86). Also available via the Internet.

Thesis (M.S.)--University of Michigan, 1981.

Thesis (Ph. D.)--Lehigh University, 1998. / Includes vita. Bibliography: leaves 201-223.

Thesis (M.F.A.)--Rochester Institute of Technology, 1987. / Typescript. Includes bibliographical references (leaf 18).

Thesis (M.F.A.)--Rochester Institute of Technology, (1960). / Typescript. Bibliography.

Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (Ph. D.)--University of California, San Diego, and San Diego State University, 2004. / Vita. Includes bibliographical references (leaves 189-200).