Novel Layered Hydroxyapatite/Tri‐Calcium Phosphate–Zirconia Scaffold Composite with High Bending Strength for Load‐Bearing Bone Implant Application

Abstract

The integration of biological and mechanical requirements remains a challenge in developing porous hydroxyapatite (HA) and tri-calcium phosphate (TCP) scaffolds for load-bearing bone implant application. With the newly developed slipdeposition and coating-substrate co-sintering technique, a strong layered HA/TCP-zirconia scaffold composite structure was successfully fabricated. The bending strength (321 MPa) of this composite can match upper strength limit of the natural compact bone. The HA-based scaffold coating has multiple scale porous structures with pore size ranging 1-10 and 20-50 lm. The zirconia-based substrate is also porous with submicropores. Focus ion beam micrographs show most of the micropores in the coating are interconnected. Microindentation and primarily adhesive strength tests demonstrate that the scaffold coating strongly bonds with the zirconia based substrate. In vitro cell culture study indicates that the coatings have no cytotoxicity. It is evident that the strong layered HA-zirconia scaffold composite offers new implant options for bone repairs requiring immediate load bearing capacity.

Design optimization of a radial functionally graded dental implant

“…The implant pore size considered in this work is 100 μm because of its need to physically fit within the optimization layers and furthermore, such a porous structure can be manufactured using the method developed by our team . This involves a low‐density‐slip coating‐deposition and coating‐substrate cosintering process to deposit micro‐porous HA/tri‐calcium phosphate based coatings on zirconia substrate presintered at 900°C.…”

“…A HA‐rich scaffold‐like coating on a strong HA‐containing substrate can be introduced during ceramic composite processing. Our group has recently developed a HA‐coating deposition method and the trials have yielded promising results using HA and zirconia to develop a system with graded porosity and material composition …”

“…Our group has recently developed a HA-coating deposition method and the trials have yielded promising results using HA and zirconia to develop a system with graded porosity and material composition. [22][23][24] In this work, we use FEA to test the hypothesis that a low-modulus coating of the implant would reduce the stresses in the peri-implant bone and we use design optimization and the rule of mixture to estimate the elastic modulus and the porosity of the coating that provides optimal stress shielding of the peri-implantar bone.…”

Application of Calcium Phosphate Materials in Dentistry

“…Hydroxyapatite is the most documented calcium phosphate and can be used in bulk form, as a coating and/or cements [27–29]. This material can be classified according to its porosity, phase, and processing method.…”

Indirect casting of patient-specific tricalcium phosphate zirconia scaffolds for bone tissue regeneration using rapid prototyping methodology

“…Malmstrom et al in his study has demonstrated that bone in-growth in microporous HA scafold is more as compared to that of zirconia scafolds with same porosities [23]. On the other hand, it has been found that zirconia being instinctively tough adds to the strength of HA and TCP ceramics [24]. Matsumoto et al in his study conirmed excellent results in respect of strength comparable to human cortical bone using composite HA/zirconia scafold having 70/30 weight ratio [1].…”