Titanium dioxide nanotubes enhance bone bonding in vivo

Implant topography is critical to the clinical Success of bone-anchored implants, yet little is known how nano-modified implant topography affects osseointegration. We investigate the in vivo bone bonding of two titanium implant surface: titanium dioxide (TiO2) nanotubes and TiO2 gritblasted surfaces. In previous in vitro studies, the topography of the TiO2 nanotubes improved osteoblast proliferation and adhesion compared with gritblasted titanium Surfaces. After four weeks of implantation in rabbit tibias, pull-out testing indicated that TiO2 nanotubes significantly improved bone bonding strength by as much as nine-fold compared with TiO2 gritblasted surfaces. Histological analysis confirmed greater bone-implant contact area, new bone formation, and calcium and phosphorus levels on the nanotube surfaces. It is anticipated that further studies will contribute to a better understanding of the effect of implant nanotopography on in vivo bone formation and bonding strength. (C) 2009 Wiley Periodicals, Inc.