Our typical per-op discussion includes discussion of the longevity of breast implants. Simply put, they are high tech plastic bags, which move with your movements throughout each day. It should be no surprise that they may wear out eventually.
Factual information and statistics for your proposed article will best come from the implant manufacturers (Mentor / J&J, Natrelle / Allergan).
Saline implant deflation is easy to diagnose and more simple to treat. Detection of gel implant leakage may require imaging studies (MRI) and may be treated with capsulectomy. New implants are used in both situations.
The concept you mention of "returning implants" is not relevant to the patient's situation. A patient dosen't just purchase implants (product), she undergoes a surgical procedure, under the care of a plastic surgeon (service). The fact that she had surgery can't be undone, but the implants can be removed. Removal would be a very unusual option and should be carefully considered after discussion with the surgeon.