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In order to support bone tissue regeneration, porous biomaterial implants (scaffolds) must offer chemical and mechanical properties, besides favorable fluid transport. Titanium implants provide these requirements, and depending on their microstructural parameters, the osteointegration process can be stimulated. The pore structure of scaffolds plays an essential role in this process, guiding fluid transport for neo-bone regeneration. The objective of this work was to analyze geometric and morphologic parameters of the porous microstructure of implants and analyze their influences in the bone regeneration process, and then discuss which parameters are the most fundamental. Bone ingrowths into two different sorts of porous titanium implants were analyzed after 7, 14, 21, 28, and 35 incubation days in experimental animal models. Measurements were accomplished with x-ray microtomography image analysis from rabbit tibiae, applying a pore-network technique. Taking into account the most favorable pore sizes for neo-bone regeneration, a novel approach was employed to assess the influence of the pore structure on this process: the analyses were carried out considering minimum pore and connection sizes. With this technique, pores and connections were analyzed separately and the influence of connectivity was deeply evaluated. This investigation showed a considerable influence of the size of connections on the permeability parameter and consequently on the neo-bone regeneration. The results indicate that the processing of porous scaffolds must be focused on deliver pore connections that stimulate the transport of fluids throughout the implant to be applied as a bone replacer.

The performance of biomaterial scaffolds for bone tissue engineering, as porous titanium implants, is strongly dependent of its structural features. A reliable structural characterization of this kind of implant is very important. The most of image analysis techniques just supplies 2D information about the structure of specimens. X-ray microtomography is imaging technique that can produce 3D images of samples, however, stochastic models can also estimate properties of porous materials in 3D. This work presents the evaluation of a 3D model (using a truncated Gaussian method) in comparison to 3D microtomography volume, both from a titanium scaffold sample. In order to compare, geometrical parameters were measured for both 3D volumes. By the results, the truncated Gaussian 3D method reproduced a model with similar values to the microtomography volume, showing a good agreement among data, which suggests the use of this technique to estimate physical parameters of titanium scaffolds

The aim of this study is to apply gamma ray transmission (GRT), a non destructive technique, in the structural characterization of low-porosity ceramic samples. GRT technique is based on the attenuation that photons of an incident radiation beam undergo when passing through the material. With this technique the porosity of alumina (Al2O3) and boron carbide (B4C) ceramic samples, was determined. The equipment employed comprises a 241Am (Americium) gamma ray source (59.6 keV and 100 mCi), a 50.8 mm × 50.8 mm NaI (Tl) scintillation detector coupled to a standard Gamma Ray Transmission system and a micrometric automated table for sample movement. The porosity profile of the samples shows a homogeneous porosity distribution, within the spatial resolution of the employed transmission system. The mean porosity values determined for Al2O3 and B4C were 17.8 (±1.3 %) and 3.87 (±0.43 %), respectively. Statistical treatment of these results was performed and showed that the mean porosity values determined by Gamma Ray Transmission technique are the same as those supplied by the manufacturer.

Porous titanium has been used for grafts and implant coatings as it allows the mechanical interlocking of the pores and bone. Evaluation of porous scaffolds for bone regeneration is essential for their manufacture. Porosity, pore size, pore shape and pore homogeneity are parameters that influence strongly the mechanical strength and biological functionality. In this study, porous titanium samples were manufactured by powder metallurgy by using pure titanium powders mixed with a pore former. The quantification of the porosity parameters was assessed in this work by geometric method and gamma-ray transmission, the non-destructive techniques and metallographic images processing, a destructive technique. Qualitative evaluation of pore morphology and surface topography were performed by scanning electron microscopy and optical microscopy. The results obtained and the effectiveness of the techniques used were compared in order to select those most suitable for characterization of porous titanium scaffolds.

Porosity and pore size are critical features for biomaterial scaffolds as they play an essential role in bone formation and bone ingrowth in vivo. Therefore, techniques for scaffolds evaluation are of great importance for their design and processing. Porous titanium has been used for grafts and implant coatings as it allows the mechanical interlocking of the pores and bone. In this study, porous titanium samples were manufactured by powder metallurgy. The porosity quantification was assessed by optical quantitative metallographic analysis, and non-destructive gamma-ray transmission and X-ray microtomography techniques, in order to compare their efficacy for porosity evaluation. Pore morphology and surface topography were characterized via scanning electron microscopy. These techniques have demonstrated to be suitable for titanium scaffolds evaluation, and micro-CT was the one that allowed the three-dimensional porosity assessment.

Titanium foams have been used for surgical implants and biomedical engineering because they exhibit inert behavior and good corrosion resistance. Substantial progress has been achieved for metallic foam fabrication techniques, however the porosity characterization methods available haven’t been studied sufficiently. A previous research has developed a powder metallurgy route to produce pure titanium foams attaining the porosity requisites for porous surfaced surgical implants. In this study, titanium foams porosity was evaluated employing different techniques: optical quantitative metallographic analysis with automatic image technique, gamma-ray transmission and x-ray microtomography. These techniques can be used for titanium foams analysis, though their results can not be simply compared, because they use quite different methodologies and take different measurement assumptions.