Which implants are the safest?

I have not used the Inspira prostheses. The concept is interesting, but not totally tried and true.
I personally prefer gel prostheses that are moderate-plus or high profile to give the ideal projection. In my practice, my gel/saline prostheses are 98%/2%. It is the patient's ultimate decision as to which prostheses to use. 
As far as saline prostheses, I think the "look and feel" of a gel prostheses is preferable. 

I personally prefer saline implants.  They have far fewer problems in the future and they really feel about the same in most women.  They also provide better peace of mind.  Many surgeons don’t feel the same way and push for silicone saying they have been proven to be safe.  It depends on what you are comfortable with.  I will do either saline or silicone as long as the patient is well informed on the difference.

Dear PreciousJenBee,there have been numerous studies on the safety and efficacy of silicone breast implants. The FDA has approved them to be safe and breast augmentation is the most common cosmetic surgical procedure performed in the United States every year. Implants are much different than they used to be with rigorous testing and cohesive gel. I can't tell you how happy my breast augmentation patients have been with their implants.
I would recommend a consult with a plastic surgeon to go over all of your concerns. Saline implants are also a perfectly good option if you are still concerned and are less expensive.Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Both silicone and saline devices are safe and reasonable options.
Patients should be aware of the inherent differences between the available implants.
Saline vs. Silicone differences include:
-The "feel"- silicone is more natural
-The "look"- silicone is less prone to rippling
-The "cost"- silicone is more expensive
-Customization-Silicone implants are pre-filled to a particular volume. Saline can be adjusted on the table within a recommended range.
-Monitoring-Saline implants, if ruptured, will deflate and the saline fill will be absorbed. Silicone implants require surveillance MRI's at 3 years and every 2 years after.
-Incisions- Because saline implants are placed empty they can be passed through slightly smaller incisions
-BIA-ALCL and Textured gels- Breast implant associated Anaplastic Large Cell Lymphoma is a rare phenomenon which has only recently come into the spotlight. The are a few hundred cases worldwide and all have been associated with textured gel implants.In summary, one is not better than the other. They simply represent different options. In my practice, most patients choose silicone devices for the reasons listed above.As always, discuss your concerns with a board certified plastic surgeon (ABPS).

Thank you for your question.
Both saline and silicone are good implants, each associated with pros/cons;  in some cases, the use of a specific type of breast implant may be indicated for a specific patient.   

In my practice, the type (saline versus silicone gel) of breast implant utilized is individualized mainly depending on the patient's starting anatomy and goals.  The type of implant used may determine the final outcome, especially if the patient does not have significant covering breast or adipose tissue. For example, 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. In other words, if a patient has very low body fat and/or very little breast tissue, the silicone gel implants may provide a more "natural" result.
 
 My best advice: select your plastic surgeon carefully. Make sure that he/she has significant experience achieving the types of outcomes you will be pleased with. Then, communicate your goals carefully, as  well. Working together you will come up with a good plan to achieve your goals.  

Best wishes.