Acute Inflammatory Response to Laser‐Induced Micro‐ and Nano‐Sized Titanium Surface Features

BACKGROUND: The inflammatory process induced by implant surfaces is an important component of the tissue response, where limited knowledge is available regarding the role of surface topography. With laser ablation, a combined micro- and nanoscale surface modification could be created, which have been shown to enhance bone growth and biomechanical stability in vivo. PURPOSE: The aim of this article was to evaluate the early in vivo inflammatory response to laser-modified titanium disks, with machined titanium disks and sham operation sites serving as controls. MATERIALS AND METHODS: Circular disks were installed in a subcutaneous rat model for 24 and 72 hours, where the cell number, cell types, and cytokine levels were evaluated. RESULTS: The results revealed that significantly fewer inflammatory cells (mononuclear and polymorphonuclear) were attracted to the sites with the laser-modified implants compared with the machined titanium implants. Similar concentrations of pro-inflammatory cytokines (TNF-a and MCP-1), together with slightly higher cell viability, were observed around the laser-modified surface compared with the machined surface. CONCLUSIONS: The results in the present study suggest that the combination of surface micro and nano features of the laser-treated surface contributes to the downregulation of early inflammatory events.