While bone healing occurs around implants, the extent to which this differs from healing at sites without implants remains unknown. We tested the hypothesis that an implant surface may affect the early stages of healing. In a new mouse model, we made cellular and molecular evaluations of healing at bone-implant interfaces vs. empty cortical defects. We assessed healing around Ti-6Al-4V, poly(L-lactide-co-D,L,-lactide), and 303 stainless steel implants with surface characteristics comparable with those of commercial implants. Our qualitative cellular and molecular evaluations showed that osteoblast differentiation and new bone deposition began sooner around the implants, suggesting that the implant surface and microenvironment around implants favored osteogenesis. The general stages of healing in this mouse model resembled those in larger animal models, and supported the use of this new model as a test bed for studying cellular and molecular responses to biomaterial and biomechanical conditions.

The importance of wheel surface topography and its influence on the grinding performance and the workpiece finish is widely recognized. Wheel surface characterization is an important aspect towards the development of adaptive control and process optimization in grinding. This paper highlights a new method of assessing the characteristics of the wheel surface by measuring air flow around the wheel using a turbulence amplifier system. Different wheel surface profiles have been generated with different dressing feed rates and their effective profiles have been compared with the output values of the turbulence amplifier. An optimum dressing feed rate range for the production of fine surfaces has been suggested. The changes in the wheel topography from freshly dressed to glazed condition, as the grinding proceeds, have been measured and their effect on the ground finish has been discussed. Based on the experimental results, the possible practical utilization of this technique in industry is suggested to ascertain the stage of wheel glazing and loading at which redressing is required for better performance.