Once a woman has decided to have breast augmentation surgery, perhaps her most personal choices are what type of implant (if using an implant at all), and what size implant to select. Although saline and silicone implants each have their own advantages and disadvantages, only women who choose saline implants will need to understand the issues associated with overfilling.

What Is Overfilling?

Implant manufacturers recommend both a minimum and a maximum fill level for saline implants. If the cosmetic surgeon fills the implant to a level within the recommended range (usually between 425 and 450 cc), it is considered to be properly filled. Underfilling occurs if the implant falls below the minimum level (i.e., below 425 in the previous example), while overfilling occurs if the surgeon adds an amount of saline over and above the highest suggested level (i.e., above 450 in the prior example). 

Why Are Only Saline Implants Affected?

Silicone implants come in standard, prefilled sizes. One of the advantages of saline implants is that the surgeon and patient have the option of filling them after they have been placed, meaning the incision will be significantly smaller.  However, the drawback is the possibility of underfilling or overfilling the implant.

Why Do Many Surgeons Overfill?

Manufacturers originally had certain fill ranges approved by the Food and Drug Administration (FDA) for sets of standard implant sizes. When regular clinical experiences showed these maximum numbers were too low to prevent wrinkles, surgeons continued to overfill the implants and notified the manufacturers of the problem. 

Dr. Dowden explains that the manufacturers, in turn, attempted to modify the fill numbers with the FDA but were unable to do so without additional testing that would cost millions of dollars. The FDA also did not allow manufacturers to make “unofficial” recommendations for optimal fill levels directly to surgeons. 

Will It Need To Be Replaced Sooner?

As Dr. Dowden points out, overfilling is actually optimal filling, which means that an implant will have a longer life if it is overfilled.

If My Surgeon Overfills My Implant, Is It More Likely To Leak?

In a study of 138 patients who underwent breast augmentation, Becker, Carlisle, and Kay (2008) found no signs of greater leakage from overfilled implants. In fact, out of the 270 total implants used in these 138 patients, 263 were given a perfect score on a survey of patient satisfaction.

The authors concluded it is not only desirable, but virtually necessary to overfill implants—though against the manufacturer’s recommendation—in order to avoid certain complications.

Overfilling implants is a common practice in the field; ask your surgeon if you have questions about the advantages and disadvantages of overfilling your saline implant.