Surface roughness enhances the osseointegration of titanium headposts in non-human primates

It is well recognized that micrometer and nanometer sized surface features enhance the skeletal attachment of implants within bone. However, little is known regarding the integration of implants placed outside the bone but in contact with the surface. Loosening of chronic skull anchored headposts in non-human primate based experiments can be a factor. The purpose of this study was to evaluate the effect of a simple and easily applied surface texture on bone apposition to titanium implants fixed to the periosteal surface of the skull. Implants possessed either a polished surface or a textured surface created by grit-basting followed by acid etching. The percent of bone in contact with the implant surface (bone apposition) to three polished and three textured implants was evaluated in one adult female monkey after 14 weeks. Upon harvest, implants were processed for undecalcified histology and regions of bone apposition were quantified using backscatter electron microscopy and digital image analysis. The bone apposition to textured implants was 62±20% and to polished implants was 42±21%. The application of a peak-and-pit like texture to the surface of titanium implants significantly increased bone apposition to titanium implants placed on the periosteal surface of the skull. This study demonstrates that titanium headposts can easily be modified to improve osseointegration using equipment and supplies available to most neurophysiological laboratories. In addition, implant texturing may have utility in areas including skeletal trauma and reconstruction where devices are placed in contact with the bone surface.