Composition Silicone shells containing sterile injectable saltwater make up saline breast implants. The saline has a concentration of 0.9%, which describes the concentration of electrolytes in the fluid; doctors refer to this as extracellular fluid. The volume of the breast implants remains the same despite the bidirectional flow of water molecules across the implant shell. To demonstrate the significance of the 0.9% concentration, a saline implant left on a shelf at room temperature will after several months only contain salt crystals after all the water molecules essentially evaporate across the silicone shell. History Because of controversy about the safety of silicone implants, in 1965 a French Surgeon named H. R. Arion proposed the first saline implant. The implant was essentially a solid silicone shell that contained saltwater. After many tests, saline implants doctors accepted saline implants as safe. The FDA approves the use of saline implants. FDA Information http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/BreastImplants/ucm063717.htm http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/ImplantsandProsthetics/BreastImplants/ucm063719.htm http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/ucm071228.htm