Histological and synchrotron radiation-based computed microtomography study of 2 human-retrieved direct laser metal formed titanium implants.

BACKGROUND: The macroscopic structure of bone has been traditionally studied through x-ray radiography or x-ray tomography. However, the resolution limits of these techniques do not enable the reconstruction of the composite bone architecture at the nanometer level. Compared with histomorphometry, x-ray micro-CT has shown its efficiency in providing nondestructive and rapid 3D images and measurements on bone microstructure. Micro-CT higher resolution has been achieved with synchrotron radiation-based computed microtomography (SRμCT). PURPOSE: The aim of this study was a histological and SRμCT analysis of 2 porous titanium implants. MATERIALS AND METHODS: Two direct laser metal forming titanium implants were inserted in the posterior maxilla of a patient and retrieved after 2 months. One of these implants was treated to obtain thin ground sections, whereas the other underwent a SRμCT evaluation. RESULTS: The histological results, showing that the implant surface presented superficial debris and particle inclusions in the surrounding tissue close to the bone area, were confirmed by micro-CT investigations. CONCLUSIONS: SRμCT allowed high resolution with good sample penetration and depth of focus and an evaluation of the relative arrangement of structures that cannot be determined by 2D imaging.