A good preparation of the implant surface in order to accommodate bone topographical features contributes to accelerate the assembly between the new bone formed and the metallic implant. Research has been consequently focused on the surface modifications of implants aimed to simulate the size of the proteins or cell membrane receptors. In vitro results about the influence of different micro-nanoscale roughness on the osteoblast differentiation are sometimes contradictory. This is probably due to the differences between the types of cells and the types of nanoscale surface modifications used in these experiments. So, the definitive confirmation should be given by in vivo studies. In this work, the in vivo study about the use of oxidation treatments to modify the nanoroughness on the previous micro-scale roughness of the implant surface has proved to accelerate the osseointegration process.

The morphometric measurement of the BIC of osseointegrated implants is the standard procedure for the evaluation of bone formation on an implant surface. High BIC values are considered to be a prerequisite for implant stability, which clinically enables functional dental reconstruction. Studies evaluating new implant surfaces assess this parameter. In particular, differences in BIC between test and reference surfaces are statistically analysed to compare their osteogenic potential. Nevertheless, it is interesting to remark that the use of two (or even only one) histological sections per implant may strongly influence the determined BIC.

In our work, densitometric and morphometric studies point to a better bone response to the Ti6Al4V commercial implants thermally treated at 700 °C for 1 h (Figs. 5 and 6). The highest BIC value achieved for the thermally treated implant after 30 days of implantation (especially in the OVX rabbit group) could be explained by considering different features on the oxidized surface such as chemical composition and topographical properties.