Quantitative screening of engineered implants in a long bone defect model in rabbits.

We have standardized a long bone defect model in rabbits to quantitatively compare the bone healing performance of engineered biological implants and have tested the bone healing efficiency of porous cylindrical scaffolds (ø-h, 6-20 mm [diameter 6 mm, height 20 mm] porosity, 70%) that were produced from hydroxyapatite (HA), titanium (Ti), and a novel biodegradable polymer-bioceramic composite (PH70alphaTCP). Scaffolds were perfused with or without 20 x 10(6) rabbit periosteal cells (RPCs) in a bioreactor and implanted in a standardized 2 cm defect in rabbit tibiae. X-rays revealed that new bone had formed at 3 weeks after creation of the defects.

Validation of x-ray microfocus computed tomography as an imaging tool for porous structures.

X-ray microfocus computed tomography (micro-CT) is recently put forward to qualitatively and quantitatively characterize the internal structure of porous materials. However, it is known that artifacts such as the partial volume effect are inherently present in micro-CT images, thus resulting in a visualization error with respect to reality. This study proposes a validation protocol that in the future can be used to quantify this error for porous structures in general by matching micro-CT tomograms to microscopic sections.

The validation of a compression testing method for cancellous human jawbone by high-resolution finite element modeling.

Purpose: The aim of this study was to determine a reliable compression testing method for cancellous jawbone specimens and to validate it by high-resolution finite element (FE) modeling based on microcomputerized tomography (microCT) images of the specimens.

Materials And Methods: Three series of human femoral bone samples were tested to establish a compression protocol for human jawbone cores. A microCT scan of each bone sample was obtained.

Micro-CT-based screening of biomechanical and structural properties of bone tissue engineering scaffolds.

The development of successful scaffolds for bone tissue engineering requires a concurrent engineering approach that combines different research fields. In order to limit in vivo experiments and reduce trial and error research, a scaffold screening technique has been developed. In this protocol seven structural and three biomechanical properties of potential scaffold materials are quantified and compared to the desired values.

Structural and radiological parameters for the characterization of jawbone.

Objectives: The aim of this study was to determine the Hounsfield values of selected bone sites on a computed tomography (CT) scan of the jaw and to investigate the relationship between this radiological parameter and structural parameters.

Materials And Methods: A selection of 24 bone samples out of eight cadaver human jaws was made. The following parameters were measured: Hounsfield value in the jaw (HU1) determined by a first CT scan, Hounsfield value of the excised bone specimen (HU2) by a second CT scan, bone mineral density (BMD) by a dual-energy X-ray absorptiometry scan, bone volume (BV/TV) by the microfocus CT scan, first peak transmission time (T(US-1)) and first zero crossing transmission time (T(US-2)) by an ultrasound measurement and Young's modulus (E(MECH)) by a compression test.