Platinum is a metal used in the manufacture of the shell and gel components of silicone breast implants. FDA fully evaluated the scientific literature on platinum. Based on the existing literature, FDA believes that the platinum contained in the implant shell and gel is in the zero oxidation state, which poses the lowest health risk. This is further supported by the available biocompatibility testing, gel bleed testing, and clinical data on these implants.

Source: http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/BreastImplants/ucm063719.htm#1