I'm amazed at the misinformation included in some of the other comments. I am not aware of a single peer-reviewed study showing that Artefill migrates, despite my colleague's contention that it does. There is a study in the literature specifically looking at migration of microsphere fillers, but it did not find migration to occur in the range of particle sized used in Radiesse and Artefill. For reference, the study is: "Migration studies and histology of injectable microspheres of different sizes in mice." Plast Reconstr Surg. 2004 Apr 15;113(5):1380-90. I would challenge my colleagues to show some good science (not speculation) that indicates migration with Artefill. Likewise, although biofilm formation is an interesting area of concern with any long-lasting filler, there are again no studies demonstrating biofilm formation around the microparticle fillers such as Radiesse and Artefill. Is this possible? Maybe. And if it is, what's the incidence? Also, it appears that Dr. Klein does not understand what a biofilm is. It is not where "the body creates a protective wall around the implant, known as a biofilm." Rather, biofilms are created by the colony of microorganisms to protect the microorganisms. I'll agree, though, that they can be a serious issue for both biologic and non-biologic implants. No filler is without risk, including serious risk, but science, not fear-mongering should guide our discussion and decision-making with patients. --DCP