**5. Conclusions**

The combination of antibacterial ability and biocompatibility, as well as non-cytotoxicity, studied in vitro, indicates that the optimal AgNPs enriching method could provide a promising strategy for the fabrication of a long-term antibacterial surface and, thus, an attractive biomaterial which successfully solves the growing problem of peri-implant infection. By taking into account the obtained results, it can be stated that all studied samples revealed very high antimicrobial activity, resulting from the release of Ag− ions from silver nanoparticles, as well as high biocompatibility. Moreover, they are all characterized by a relatively simple synthesis. However, among studied systems, Ti6Al4V/TNT5/0.6AgNPs contained the lowest amount of AgNPs, but revealed to still have optimal biointegration properties and high biocidal properties. Thus, it can be taken into account as a biomaterial possessing the desired biological properties and, at the same time, as a biomaterial in which the potential harm is minimized by minimizing the number of silver nanoparticles.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/8/3/334/s1, Table S1: The results of the contact angle measurements, which were made three times using distilled water and diiodomethane and the results of the surface free energy (SFE) of biomaterials used in Owens-Wendt method, Figure S1: Reduction of colony number of *Escherichia coli* ATCC25922=PCM2057 after treatment with silver ions released from Ti6Al4V/AgNPs (b–e) and Ti6Al4V/TNT5/AgNPs (g–j) for 24 h. Number of bacterial colonies after treatment with Ti6Al4V/AgNPs and Ti6Al4V/TNT5/AgNPs was reduced at least 100 fold when compared to Ti6Al4V (7.0 × 10<sup>5</sup> c.f.u. mL−1) (a) and Ti6Al4V/TNT5 (3.8 × 10<sup>5</sup> c.f.u. mL−1) (b).

**Author Contributions:** Conceptualization, A.R.; methodology, A.R.; formal analysis, A.R. T.J., P.G.; investigation, A.R., M.G., M.E., T.J., M.W., P.G.; writing—original draft preparation, A.R.; writing—review and editing, A.R.; visualization, A.R.; supervision, A.R.; project administration, A.R.; funding acquisition, A.R.

**Funding:** This research was funded by the Regional Operational Programme of the Kuyavian-Pomeranian Voivodeship (1.3.1. Support for research and development processes in academic enterprises), within the gran<sup>t</sup> obtained by Nano-implant Ltd. The APC was funded by Nano-implant Ltd.

**Conflicts of Interest:** The authors declare no conflict of interest.
