Pure brand implants are polyurethane implants produced by Sientra, the third company to receive FDA clearance to market their cohesive silicone gel implants (but NOT their polyurethane ones) in the USA.Polyurethane implants have not been used in the US since 1991, when the FDA restricted the use of silicone gel implants, and all but two implant manufacturers (Mentor, and McGhan, now Allergan) went bankrupt or stopped their US sales. This included many lesser-used implants such as polyurethane, Misti-gold, Dual-lumen silicone/saline, etc. But many countries throughout the world still have the availability of polyurethane implants, which did reduce the incidence of capsular contracture (CC), particularly when used above the muscle, as most breast augmentations were done before the early 1990's.When Sientra received FDA clearance for the use of its Silimed line of breast implants in the USA in March, 2012, this approval was not for other implants Sientra produced worldwide since 1978. This includes Pure or any other type of polyurethane implant.The success of polyurethane textured implants minimizing capsular contracture is what led implant manufacturers to develop silicone gel surface texturing in the late 1980's. That, and some bad press about toluene-2,4-diamine (used in the production of toluene diisocyanate, which is used in the production of polyurethane) being a potential carcinogen caused polyurethane to fall out of favor in the US. And, the polyurethane coating seemed to break down after several years, perhaps losing its CC protectiveness. Despite these really ending up being red herrings, polyurethane was never re-studied for FDA re-approval in the US and remains available only outside the US. I hope this helps. You have many alternatives; speak with your ABPS-certified plastic surgeon; he or she really can tell you about the superior implants presently available. Best wishes! Dr. Tholen
