As a co-investigator for Allergan, member of clinical advisory panels for Allergan (NOVO) and Sientra, as well as being a certified user of gel implants for Mentor, I can say what is known. Sientra as their full line of implants which are all highly cohesive gel implants available. Allergan has 4 models of 12 approved, Mentor has 1. Allergan and Mentor source their silicone gel from the same company, only Sientra source theirs from a similar company, but has unique properties related to its compounding. After 10 years and over 700 of these implants placed, I have seen double capsules in only Allergan, none in Mentor or Sientra. No deflations have been seen, nor contractures in breast augmentation procedures. No noted ALCL cases in these patients either. As a member of the most recent supplement for plastic surgeons regarding these gummy bear implants, in my opinion, Sientra provides a one breast feel, soft, strong, with the best warranty (both contracture and deflation), and selection that is available today.