As a result of progress in biomedical technology, it is now possible in many medical disciplines to replace the function of damaged or missing organs and tissues by using implants, thus considerably improving the patient's quality of life. However, implant-associated infections are still one of the most important challenges in modern medicine. These infections are caused by bacterial biofilms colonizing the implant surface. This results in inflammation, accompanied by destructive changes in the surrounding tissue. It has not yet been possible to treat this effectively, as the bacteria in the biofilm are specifically organized within a protective extracellular matrix and their metabolism is modified. Here I will discuss about bacterial biofilms, biofilm-associated implant-infections and about new strategies to develop innovative implant surfaces for various medical disciplines, with both long-term anti-biofilm activity and good biointegration. Approaches include physical functionalization of the implant surface with modern laser-based procedures, as well as chemical functionalization, including drug delivery systems. I will also show various validated in vitro and in vivo test systems for analysis of implant-associated infections like a multispecies biofilm model, a coculture system and an in vivo periimplantitis model.