Porous bio-ceramic coating on zirconia formed through freeze-drying

This study presents a new bio-ceramic processing technique, which can be used to deposit thick porous hydroxyapatite(HA) coatings on strong three-dimensional (3D) zirconia substrates with a strong coating-substrate interface bonded by bio-glass infiltration during the sintering process. A thin bio-glass coating was first painted on the micro-porous zirconia substrates, pre-sintered at 900 °C, then followed by thick HAslip coating with gelatin and ceramic and polymer additives. Freeze-drying was used to create porous scaffold structures within the thick HA coating. The green tri-layer ceramic composites were then co-sintered at 1300 °C, resulting in thick scaffold-like HA-coating bonded strongly on load-bearing zirconia substrate or implant core. Such bio-ceramic composites with suitable strength and bio-active and bio-resorbable surface coating can provide useful implant options, bridging the gap between weak and fragile HA scaffolds and strong titanium implants.