The Effectiveness of Poly-(4-vinyl-N-hexylpyridiniumbromide) as an Antibacterial Implant Coating: An In Vitro Study

The clinical success of osseointegrated dental implants depends on the strong attachment of the surrounding hard and soft tissues. Bacterial adhesion on implant surfaces can cause inflammatory reactions and may influence healing and long-term success of dental implants. Promising implant coatings should minimize bacterial adhesion, but allow epithelial and connective tissue attachment. Therefore, the present study has examined the bioactive effect of poly-(4-vinyl-N-hexylpyridiniumbromide) regarding typical oral bacteria as well as cytotoxicitiy to human cells considering different methods of connecting polymers to silicate-containing surfaces. The results revealed that the application of putative antibacterial and biocompatible polymer in coating strategies is affected by a variety of parameters. Published findings regarding reduced bacterial adhesion could not be verified using oral pathogens whereas hexylated polymers seem problematic for strong adhesion of soft tissue. Concerning innovative coatings for dental implants basic aspects (surface roughness, thickness, alkylation, combination with other polymers) have to be considered in further investigations

Additive manufacturing of titanium alloys for biomedical applications

Titanium alloys have been extensively used in medical field, especially for load-bearing implants due to their excellent properties such as high strength and great corrosion resistance. In addition to the well-known CP-Ti and Ti-6Al-4V alloy, many beta type titanium alloys comprising of non-toxic and non-allergic elements have being developed for the next generation of bone implant materials. However, the hard machinery and high cost of materials removal arising from the conventional manufacturing processes are the two main obstacles of various potential applications of titanium alloys. As emerging advanced manufacturing technologies, additive manufacturing techniques are providing the ideal platform for the creation of these customized devices, where three dimensional complex parts could be realized by sequential production of two dimensional layers. Thus, additive manufacturing facilitates the manufacturing of parts with almost no geometric constraints and is economically feasible down to a batch size of one. This chapter mainly review the recent progress of the additive manufacturing (via selective laser melting and electron beam melting) of titanium alloys and their products, including the processing optimization, microstructure, mechanical properties and fatigue properties for different types of titanium alloys (CP-Ti, Ti-6Al-4V and Ti-24Nb-4Zr-8Sn) and their porous structures