With medical devices, failure is not an option

X-ray CT is particularly suitable for verifying the dimensions of stents, dental implants, pacemakers and many other medical devices. In the dental segment, CT is used to verify the correct positioning and orientation of prostheses on structures produced by dental technicians. The technology provides geometric information that enables precise adjustment of each individual design before its manufacture and placement in the patient's mouth. Materials researchers are also developing titanium foam implants, which offer favorable biocompatibility, improved surface roughness and high mechanical strength.

3D MEDLAB, a pioneer in additive manufacturing in the medical device sector, used an MCT 225 system to scan various 3D-printed implants made from metal or polymer, with the aim of performing both material porosity and surface roughness analysis. The image of a titanium-niobium (TiNb) dental implant, provided by 3DMedlab and AST Innovations, was obtained with a resolution of 7.1 µm, demonstrating the high level of internal detail visible in the reconstructed data. The CT examination of the dental implant was performed with a circular trajectory, at an X-ray power of 7 W and with a voxel resolution of 7.1 µm, using a Nikon MCT 225 equipped with a 225 kV / 225 W reflection target. The scan was performed with this configuration together with a Varex XRD 1620CT flat panel detector. The detector captured 3,141 projections (individual radiographs) with an exposure time of 2000 ms, resulting in a total scan time of 2 hours. This time is longer than a conventional CT scan (1–5 minutes), due to the extremely high resolution and material complexity. The data were reconstructed with Nikon CT Pro 3D software and processed in Volume Graphics Studio Max 2022.3. A complete porosity analysis was performed on the entire implant and a partial surface roughness analysis. Scans were also performed on a Nitinol (shape memory alloy) cardiac stent, with a resolution of 11 µm. The CT examination of the stent was performed with the same equipment, at an X-ray power of 11 W and with a voxel resolution of 11.4 µm. The detector captured 3,141 projections, with an exposure time of 1415 ms, resulting in a total scan time of 1 hour and 15 minutes. A nominal-actual comparison was performed between the reconstructed volume and the respective CAD file, demonstrating the geometric differences between the original model and the 3D-printed implant.

Dimensional verification of stents, dental implants, pacemakers and other medical devices. Material porosity and surface roughness analysis of 3D-printed implants manufactured in metal or polymer. Verification of correct positioning and orientation of dental prostheses. Nominal-actual comparison between reconstructed volumes and CAD files. Development of titanium foam implants.

By enabling internal visualization of critical components and complex assemblies, X-ray CT eliminates the limitations associated with accessing difficult-to-inspect areas. For this reason, Nikon's CT systems are an essential tool in the analysis and validation of medical devices, enabling examination of failures and determination of whether these result from manufacturing errors or improper use. High image resolution and ultra-fast CT reconstruction provide essential insight to ensure reliable and repeatable performance.

NM3D provides Nikon's X-ray CT systems, including the VOXLS range and the MCT 225, for inspection of critical medical devices. We offer specialized technical support for porosity analysis, surface roughness and nominal-actual comparison, ensuring the quality and reliability of your medical components.