The Influence of Lateral Spacing of TiO2 Nanotube Coated Surfaces on the Early In Vivo Osseointegration

Due to the bio-inert nature of titanium (Ti) and subsequent accompanying chronic inflammatory response, the implant’s stability and function can be significantly affected, leading in time to a poor osseointegration process. To overcome this challenge and improve the overall performance of Ti implants, various surface modifications have been employed, amongst them the deposition of titanium oxide (TiO2) nanotubes (TNTs) onto the native surface through the anodic oxidation method. While numerous in vitro and in vivo studies have already reported the importance of nanotube diameter on cell behaviour and osteogenesis, information regarding the effects of nanotube lateral spacing on the in vivo osseointegration process is insufficient and hard to find. Considering this, in the present study two types of TNTs with different lateral spacing, e.g. 25 nm (TNTs) and 92 nm (spTNTs) were fabricated and comparatively investigated in terms of their effect on the early peri-implant new bone formation. The microscopic examination at 1-month post-implantation revealed that both nanotubular surfaces, particularly spTNTs, were capable of inducing new bone formation without a significant bone destruction. Overall, our results indicate that the lateral spacing of the TNT-coated Ti surfaces can influence the in vivo outcome, thus representing a significant factor in implant design.