Wanted to know if breast implants weigh less than breast tissue?

No: The density (weight per volume) of silicone-gel filled implants is similar to body tissues. Saline implants have water density, slightly higher--the human body floats (barely) on water. But breast tissue, having a higher fat content, is more buoyant than the rest of the body, and thus lighter than either implant type. But women are seldom aware of the weight, since the chest muscles support them