Currently, there are only two U.S. based companies who manufacture breast implantsfor use in the United States: Allergan (formerly McGhan and then Inamed), Mentor (now owned by Johnson & Johnson). Sientra is a U.S. based company that purchased the license to market Brazilian made Silimed implants in the United States. Sientra (Silimed) implants were recently approved by the FDA to sell implants in the United States in 2012. All are quality devices. The differences between the first two are minimal. I have used both with satisfaction. Currently, I am using the Allergan implants. It is my understanding that Allergan licenses their intrashield barrier technology to Mentor. That barrier is what controls the amount of gel diffusion/bleed through the shell wall. What Mentor didn’t do is place that barrier on their patch (see below). If you have any bias about which brand implant to use, and you find a surgeon you like but he/she uses the other brand of implants, I would not let that sway you in the decision to use that surgeon; use the implant that he/she is most comfortable with and don’t worry about who manufactured it, you will do equally well with either one. As of this writing (September 2014), I have no experience with Sientra’s devices.
All breast implants start off by either dipping a mold (called a mandrel) into silicone or spraying the mandrel with silicone. Either way, you end up with a silicone envelope with a small (about one inch) hole in it. If the implant is destined to be a saline implant, that hole is sealed with a silicone patch with a valve built into it. This valve is used to fill the implant at surgery, as all saline implants are sold deflated. If the implant is destined to be a silicone gel filled implant, the hole is patched with a round silicone patch. Next, using a special needle, the patch is punctured and a predetermined amount of silicone gel is inserted into the silicone envelope and the needle removed. The implant is either left with its smooth surface, or if a textured surface is desired, a special thin sheet of textured silicone is then bonded to the implant, giving it its textured (fuzzy) surface. The implant is then sealed into a plastic peel-pack and inserted into a box and shrink-wrapped, then sterilized prior to sale.