Titanium and its alloys are dominant material for orthopedic/dental implants due to their stable chemical properties and good biocompatibility. However, aseptic loosening and peri-implant infection remain problems that may lead to implant removal eventually. The ideal orthopedic implant should possess both osteogenic and antibacterial properties and do proper assistance to in situ inflammatory cells for anti-microbe and tissue repair. Recent advances in surface modification have provided various strategies to procure the harmonious relationship between implant and its microenvironment. In this review, we provide an overview of the latest strategies to endow titanium implants with bio-function and anti-infection properties. We state the methods they use to preparing these efficient surfaces and offer further insight into the interaction between these devices and the local biological environment. Finally, we discuss the unmet needs and current challenges in the development of ideal materials for bone implantation.

Biomaterial-associated infection and lack of sufficient osseointegration contribute to a large proportion of implant failures. Therefore, antibacterial and osseointegration-accelerating properties are important in implant surface design. In this study, a micro/nanoporous titanium surface was prepared through alkaline and heat treatments, covalently conjugated with aminosilane. Then, varying amounts of chlorhexidine (CHX) were covalently grafted onto the aminosilane-modified surface via glutaraldehyde to obtain different CHX-grafted surfaces. These as-prepared surfaces were evaluated in terms of their surface chemical composition, surface topography, CHX grafting amount, antibacterial activity, and osteoblast compatibility. The results showed that the CHX grafting amount increased with increasing CHX concentrations, leading to better antibacterial activity. CHX (1 mg/mL) resulted in the best antibacterial surface, which still retained good osteoblast compatibility. Meanwhile, competitive bacterial-cell adhesion analysis demonstrated that this surface has great value for osteoblast adhesion at the implant–bone interface even in the presence of bacteria. This effortless, easily performed, and eco-friendly technique holds huge promise for clinical applications.

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