How much can 630cc mentor high profile implants be filled? Can they be filled past 700cc?

Thank you for your question. There is a certain fill range or tolerance to which a saline implant can be overfilled. The real question is can your breast support 700cc. To be honest, I doubt it can. If that is the case and you're getting an implant that it too large for the support structures of your breast, you can have a lot problems including implant show, implant malposition  (bottoming out and lateralizing) and in the worst cases implant extrusion. 

1. overfilling an implants, yet being a quite popular decision amongh saline implant users (surgeon) is not anything I'd recommend due to the changes of shortening the lifetime of the implant2. I understand you seek XL size; I'll have you now saline implants are normally smooth covered at the shell, and the smooth shells are non adherent, they form very poor (if any) ribcage fixation, that is why they easily bottom out and need revision, specially if the surrounding tissues are weak or... the implant is very large! this means you are buying all the tickets to develop bottoming and and regretting your decision in the near future (do research bottom out cases and you'll notice they almost all have in common smooth implants, saline and large sizes, at least in severe bottoming out grades).Finally, keep in mind the other well known downsides of saline implants, like massive rippling, only available in round shapes (thus in XL volumes they look fake a lot), bubbling, artificial touch, coldness in wintertime, etc. I strongly recommend you use latest generation (5th) anatomical shaped, cohesive gel filled and macrotextured implants, recommendably for its minimal aggression and safety in the subfascial plane.

Silicone breast implants are pre-filled, and can not be over-filled. Consult with an experienced and expert board certified plastic surgeon to understand your options.