In vivo analysis of bone-tissue interface in medical grade titanium and porous titanium with and without cenosphere as space holder

Abstract

The present study aims at understanding the in vivo behavior of titanium (Ti) foam (with and without addition of cenosphere as space holder) developed by powder metallurgy route which follows compaction at an applied pressure of 100 MPa and sintering at 1100 °C for 4 h. Cenosphere with the particle size 150–212 µm was used as spaceholder and its content was 20 wt%. The porosity content of the titanium foam developed in the present study with and without addition of cenosphere was 40% and 27%, respectively. However, they possess reduced yield strength in compression as compared to medical grade titanium. In vivo study was carried out by implanting the samples in bone defect of rabbit femur. All the titanium based samples were well-integrated within the host bone tissue which is revealed in radiography and micro-CT (µ-CT) images of the implants after three months of insertion. Fluorochrome labeling using oxytetracycline marker showed better and comparable new osseous tissue formation in medical grade Ti and porous Ti with cenosphere as space holder after three months as compared to porous Ti. The scanning electron microscopic image of the bone sample interface showed strong bonding with the signature of marginal bone in-growth inside the tissue. Finally, the in vivo behavior was correlated with initial microstructure and composition of the material. The performance of the titanium foam was evaluated by the detailed analysis of the physicochemical properties and in vivo behavior.