There are several distinct types of ways we classify breast implants.
- silicone or saline filled
- round or anatomic shaped
- smooth surfaced or textured
For the material and shape issues, there clearly are performance characteristics that differ. As to the issue of the implant shell surface, it gets a little more confusing.
The routine use of rough or textured surfaces on breast implants in the prevention of capsular contracture has been debated for nearly 20 years.
In the early 1980's we first read in the literature that the surface texture of an implant is an important variable in determining the soft-tissue response to an implant's capsule surface and experiments suggested that texturing resulted in tissue ingrowth and adherence to the implant surface.
These observations were first made with polyurethane-coated breast implants which had rough surfaces and almost no observed capsular contractures in patients with breast implants. Texturing was then quickly translated to contemporary silastic (silicone rubber) covered implants, but whether or not the same effect was maintained has been a little murky.If (a big if) there's a protective effect from texturing, the best data I've seen suggests that it's gone as you get closer to a decade out during surgery. If I had to guess why that's so, I'd say that reflects the ruptures starting to show up in those 4th generation implants at a decade out.
It's kind of interesting to see the split between the United States and the rest of the world on this issue. Our singular experience with saline implants from 1990-2006 led many surgeons to abandon textured implants for smooth round devices as they're less likely to show visible wrinkles or ripples thru the skin. The "velcro-like" effect of the implant on it's surrounding tissue causes these ripples when the implant shifts. The rest of the world has a strong preference for textured devices as they never went through dealing with the limitations of saline implants. Philosophically, those doctors made the decision that they're willing to accept more rippling as a trade off for (possibly) less capsular contracture (implant hardening).
I personally am kind of ambivalent on this. Being an American-trained surgeon, I saw mostly round smooth implants placed partially under the pectoralis muscle during my residency. Over time, I've come to believe there's a role for "subfascial" implant techniques(over the muscle, but under the muscle fascia) with smooth implants. Looking ahead, I think we're poised to see a lot of plastic surgeons getting reacquainted with textured implants with the new shaped "gummy bear" implants which are all textured to help prevent rotation of the implant in the body.