Highly porous titanium scaffolds for orthopaedic applications

Abstract

For many years, the solid metals and their alloys have been widely used for fabrication of the implants replacing hard human tissues or their functions. To improve fixation of solid implants to the surrounding bone tissues, the materials with porous structures have been introduced. By tissue ingrowing into a porous structure of metallic implant, the bonding between the implant and the bone has been obtained. Substantial pore interconnectivity, in metallic implants, allows extensive body fluid transport through the porous implant. This can provoke bone tissue ingrowth, consequently, leading to the development of highly porous metallic implants, which could be used as scaffolds in bone tissue engineering. The goal of this study was to develop and then investigate properties of highly porous titanium structures received from powder metallurgy process. The properties of porous titanium samples, such as microstructure, porosity, Young's modulus, strength, together with permeability and corrosion resistance were investigated. Porous titanium scaffolds with nonhomogeneous distribution of interconnected pores with pore size in the range up to 600 μm in diameter and a total porosity in the range up to 75% were developed. The relatively high permeability was observed for samples with highest values of porosity. Comparing to cast titanium, the porous titanium was low resistant to corrosion. The mechanical parameters of the investigated samples were similar to those for cancellous bone. The development of high-porous titanium material shows high potential to be modern material for creating a 3D structure for bone regeneration and implant fixation.

Ki̇şi̇ye Özgü Dental İmplantlar: Derleme

“…[39][40][41][42] Atatürk -192 Direkt metal lazer sinterleme (DMLS), toz metaller, radyant ısıtıcılar ve bilgisayar kontrollü lazer ile bir objenin tabaka tabaka oluĢturulmasını sağlayan lazer destekli katmanlı üretim tekniğidir. [39][40][41][42][43] Temelde, makine, materyalin katmanlarını tabakalama tekniği ile uygulayarak hareketli platform üzerinde objenin üretimini sağlar. [39][40][41][42][43] Her bir tabaka için, makine doğru kalınlığa sahip (0.1 mm) toz tabakasını ortaya koymaktadır.…”

“…[39][40][41][42][43] Temelde, makine, materyalin katmanlarını tabakalama tekniği ile uygulayarak hareketli platform üzerinde objenin üretimini sağlar. [39][40][41][42][43] Her bir tabaka için, makine doğru kalınlığa sahip (0.1 mm) toz tabakasını ortaya koymaktadır. Daha sonra, yüksek güce sahip lazer ıĢını bu toz yatağı üzerine yönlendirilir ve bilgisayar destekli tasarım dosyasına uygun olarak odak bölgesinde bulunan metal tozlarını kaynaĢtırmak için programlanır.…”

“…Bu süreç, obje üretilinceye kadar, tabaka tabaka devam eder. [39][40][41][42][43] Direkt metal lazer sinterleme, her bir tabakadaki porözitenin ve aynı zamanda por bağlantısının, boyutun, Ģeklin ve dağılımın ve buna bağlı olarak implantın üç boyutlu yapısının kontrolünün sağlanmasını imkanlı hale getirir. Bu durum lazer gücü ve pik gücü, lazer nokta çapı, katman kalınlığı, tarama mesafesi, tarama hızı ve tarama stratejisi veya orjinal titanyum partikül boyutunun modifiye edilmesi gibi parametrelerin değiĢtirilmesi ile sağlanır.…”

Estimation of Young’s Modulus of the Porous Titanium Alloy with the Use of Fem Package

“…The size of a scaffold pore should be selected in such a range that growth of new bone cells within it could take place. The optimal value of pore size for bone ingrowth is 100÷600 µm [2,3,4,9,16]. Scaffolds based on spherical pores were designed with assumption of some specific diameter 300 µm of interconnected holes/channels.…”

“…Porosity also provides proper environment for bone ingrowth in order to achieve a good fixation between porous implant and the surrounding bone. Nowadays, there are a number of manufacturing techniques for the fabrication of porous structures (both for metal and non-metal materials): selective laser melting (SLM) [8,10,14], selective laser sintering (SLS) [11], powder metallurgy (PM) [4], freeze casting [5], space holder [6], sponge replication [7]. These methods are applicable to other biomedical materials like stainless steels, biopolymers or ceramics as well [8,10].…”