There has been one study done with implants placed in a hyperbaric chamber. This study included silicone, saline and silicone/saline filled at various depth/time profiles that would be seen during recreational diving. The study indicated a 1-4% increase in size of bubbles during the study. Saline implants absorbed less nitrogen, N2 being more soluble in the silicone. The amount of volume increase was not enough to cause rupture and the bubbles resolved over time. This study did not answer the question of implants in situ in in vivo conditions (Implanted in the living human).
Silicone implants are heavier than water and possibly can alter buoyancy and attitude in the water, particularly if large. Diving should not be attempted until completely released by the surgeon and some thought should be directed toward change in body configuration, wet suits, gear straps and appropriate weighting so as to avoid undue pressure over the implant bag and buoyancy problems.