Alloplastic breast augmentation has always been done by two fundamental types of implants, silicone and saline. Each implant type has their advantage and disadvantages. Silicone breast implants can feel more natural and do not suffer spontaneous failure (deflation) but usually cost more and have the rare risks of adverse immunologic reactions to them. Conversely saline implants usually cost less and do not induce immunologic reactions but can suffer spontaneous deflation and are associated with higher rates of rippling. A lesser known effect of saline implants is that the have higher rates of bottoming out. To date the reason for that effect has never been evaluated.
In the August 2024 issue of Plastic & Reconstructive Surgery Global Open a study on this topic was published entitled ‘A Comparative Analysis on the Gravitational Effect on Silicone vs Saline Breast Implants’. In this study the authors looked at three different silicone and saline implants from the same manufacturer and were compared by weight and dropped onto plates from various heights to measure the vertical force of impact. (in Newtons) The assumption being that this test may replicate the impact of implants on inferior pole breast tissue from day to day activities. In his way the material, implant weight and drop height were analyzed and compared.
The study found that saline implants, regardless of weight and drop heights, impacted more force on the plates than weight-matched silicone implants. It is hypothetized that this is the result of the silicone material being a better shock absorber than saline and results in less force being transmitted onto the surrounding tissues repetitively over time. Thus a scientific explanation for the greater bottoming out effect anectodally seen in saline breast implants.
In this cleverly designed experiment the authors provide one explanation that separates the physical properties of a saline vs silicone gel filled implant. There may be other explanations as well that contribute to this effect. (e.g., differences in capsular thicknesses) But the dynamic properties of the contained materials is a valid investigation as the impact of wave forces on structures are known to differ based on fluid density and viscosity which are clearly different between these two breast implant fill materials even if their weights are not dramatically different.
Dr. Barry Eppley
World-Renowned Plastic Surgeon