In vivo biomechanical stability of osseointegrating mesoporous TiO2 implants

Mesoporous materials are of high interest as implant coatings to receive an enhanced osseointegration. In this study, titanium implants coated with mesoporous TiO2 thin films have been evaluated both in vitro and in vivo. Material characterization showed that, with partly crystalline TiO2 (anatase), long-range-ordered hydrophilic mesoporous thin films with a pore size of 6 nm were obtained. Evaluation of the mechanical resistance showed that the films were robust enough to withstand the standard implantation procedure. In vitro apatite formation was studied using simulated body fluids, showing that the pores are accessible for ions and that formation of apatite was increased due to the presence of the mesopores. An in vivo study using a rabbit model was executed in which the removal torque and histomorphometry were evaluated. The results show that the biomechanical stability of the TiO2 coating was unaffected by the presence of mesopores and that osseointegration was achieved without any signs of inflammation.