Will breast tissue eventually fill back in after explantation? 3 days post-op.

You are very early in your recovery, but the breasts will most likely not gain volume.  In fact, you may look a little flatter once swelling decreases.  The skin of the breast will probably contract some.  If after you have healed you are unhappy with the look, you can consider fat grafting, a lift, or an implant at that time.

Thank you for your question. Seems like you've been through quite a lot! While the skin may contract a bit, your breast tissue will likely not return. The only way to add more volume (or redistribute the volume you have) is through a lift, or with another implant or fat grafting. I would give things some time to heal, however - at least 3-6 months and then see how you feel at that point. Best of luck! 

The breasts will remain flat and maybe a bit more as the swelling subsides.  The only way to add moe volume is to either inject fat or put in another implant. You may benefit from a lift as well.