The Periometer® quantitative percussion system was used to interrogate the interfacial stability of implants in vitro for comparison with X-ray computer tomography (CT) data. Selected implants were placed as per standard practice in bone stimulant polyurethane blocks. The dimensions of the surgical sites surrounding the implants were analyzed using X-ray computer tomography (CT) to determine the quality of support at the implant–bone interface. In particular, the misfit between the size of the surgical site and the corresponding implant was determined for each sample. The resulting average surgical site error from the CT scans was found to exhibit good agreement with the presence of irregularities found in the percussion data.Highlights► Percussion response versus time exhibited irregularities for some in vitro samples. ► X-Ray CT was used to assess the interface integrity for six implant–bone specimens. ► Irregularities in percussion data correlate well with the CT based assessments.

The thermal stability of nanoscale grains in cryomilled aluminum powders containing 1% diamantane was investigated. Diamantane is a diamondoid molecule consisting of 14 carbon atoms in a diamond cubic structure that is terminated by hydrogen atoms. The nanostructures of the resulting cryomilled powders were characterized using both transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. The average grain size was found to be on the order of 22 nm, a value similar to that obtained for cryomilled Al without diamantane. To determine thermal stability, the powders were heated in an inert gas atmosphere at constant temperatures between 423 and 773 K (0.51Tm to 0.83Tm) for exposure times of up to 10 h. The average grain size for all powders containing diamantane was observed to remain in the nanocrystalline range (1–100 nm) for all exposures and was generally less than half of that for cryomilled pure Al heated under the same conditions. The thermal stability data were found to be consistent with a grain growth model based on drag forces exerted by dispersed particles against grain boundary migration. The present findings indicate that the presence of diamantane results in a substantial increase in the thermal stability of nanoscale grains in Al.