Overfilling a saline implant is certainly possible and sometimes performed for patients with minimal volume asymmetries. It also helps with rippling sometimes.
Mentor 1600 Moderate Profile - Can You Overfill 225cc Implant to 265cc?
Doctor Answers 4
Overfill 225cc Implant to 265cc
Of course you can overfill the implant past the recommended volume of maximum fill. But than the warranty will be voided. So I would NEVER recommend this action. From MIAMI Dr. Darryl J. Blinski, 305 598 0091
Overfill of implants.
Dr. Yuan has elegantly summarized my concerns as well. If it can be done, should it be done. Generally speaking overfill by 10% is considered reasonable. Beyond that, you will see distortions of the dimensions for which the implant fill was originally designed. This can produce scalloping of the edges as well.