Medicinal porous titanium implant and method for preparing same

Abstract

The invention discloses a medicinal porous titanium implant and a method for preparing the same. The porous titanium implant is prepared by a powder coinjection molding method; and a nano HA and TGF loaded sustained-release gelatin microsphere compound coating is deposited on the porous outer layer of the product. The outer layer of the implant has a communicated porous structure, the thickness of the porous layer is 0.4 to 1.1 millimeters, the porosity of the porous layer is 50 to 70 percent, and the aperture of the porous layer is 50 to 400 mum; the surface of the porous layer is deposited; and the binding strength of the outer layer and an inner core is 150 to 300MPa. Compared with the prior medicinal titanium implant material, the material of the medicinal porous titanium implant has higher mechanical strength, is in accordance with the mechanical performance of osseous tissue, avoids stress concentration and stress shielding, promotes stress transmission and growth of new bones, reduces time for osseointegration, and ensures the long-term stability of the implant. The method adopts once-for-all molding without post machining, thereby considerably reducing the cost.

Description

technical field [0001] The invention belongs to medical porous metal biological implant materials, in particular to porous titanium implant materials. Background technique [0002] Existing titanium implants are usually manufactured by mechanical processing, which has many procedures, large processing volume, large material loss, high cost, and is a fully dense body structure. The elastic modulus of fully dense implants does not match the surrounding bone, and stress concentration and stress shielding effects are likely to occur at the interface between the implant and bone tissue, which affects the long-term stability of the implant. In order to improve the stability of implants, the surface treatment of implants is now mostly carried out by methods such as large particle sandblasting and acid etching, anodic oxidation, surface nitriding, plasma spraying titanium slurry or hydroxyapatite (HA). Although these methods increase the roughness of the surface or improve the surf...

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Problems solved by technology

However, the strength of porous metals is not as good as that of corresponding dense metals, and the strength decreases significantly with the increase of porosity.

[0004] In order to solve the contradiction between high porosity and strength and realize the preparation of porous medical titanium implants, there is currently a method of preparing porous coatings on the surface of dense substrates by plasma spraying, but this method cannot be controlled during the process. The porosity, pore size and open interconnected pore structure of the coating, and the process temperature is mostly above 1000°C. After cooling, the residual stress at the interface between the substrate and the coating affects the bonding strength between the coating and the substrate. Therefore, this implant It is still easy to fall off during the implantation process

[0005] Powder metallurgy methods such as cold pressing + sintering, cold pressing + self-propagating high-temperature synthesis, cold isostatic pressing + sintering + hot isostatic pressing, etc., although porous metal materials with higher porosity and open interconnected pore structure can be prepared, generally It is an overall high-porosity material, and its mechanical properties often cannot meet the requirements of implants, and it is difficult to achieve near-net shape. Subsequent processing is required, and subsequent processing will destroy the porous structure.

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