Thank you for your question.
The weights of the implants are almost identical.
Saline implants have some advantages over silicone implants. Silicone implant ruptures are harder to detect. When saline implants rupture, they deflate and the results are seen almost immediately. When silicone implants rupture, the breast often looks and feels the same because the silicone gel may leak into surrounding areas of the breast without a visible difference. Patients may need an MRI to diagnose a silicone gel rupture. Saline implants are also less expensive than the silicone gel implants.
Some surgeons feel that silicone implants have a more natural look and feel than saline implants because silicone gel has a texture that is similar to breast tissue. Each patient differs in the amount of breast tissue that they have. If a patient has enough breast tissue to cover the implant, the final result will be similar when comparing saline implants versus silicone gel implants. If a patient has very low body fat and/or very little breast tissue, the silicone gel implants may provide a more natural result.
Other differences involve how the breast implants are filled. Saline implants are filled after they’re implanted, so saline implants require a smaller incision than prefilled silicone breast implants. Also, many saline implants can be adjusted after surgery. The doctor can use a syringe to put in more liquid or take it out. The size of standard pre-filled silicone implants cannot be changed.
On May 10, 2000, the FDA granted approval of saline-filled breast implants manufactured by Mentor Corporation and McGhan Medical. To date, all other manufacturers’ saline-filled breast implants are considered investigational.
As of 2006, the FDA has approved the use of silicone gel implants manufactured by the Mentor Corporation and Allergan (formerly McGhan) for breast augmentation surgery for patients over the age of 22.
I hope this helps.