Foam-covered mammary implants.

Our investigations suggest that polyurethane coating of implants prevents longitudinal fibrosis, circumferential capsule formation, and contracture as long as the underlying smooth silicone surface remains firmly and completely covered. Although not studied extensively, our experimental observations give no indication that polyurethane-coated implants promote septic inflammation more so than uncoated implants. Polyurethane-coated implants are less tumorigenic in mice than uncoated implants. However, because humans are highly resistant to foreign body tumorigenesis in general, either implant type can be considered virtually noncarcinogenic in humans.