This article claims silicone breast implants are bulletproof, even though it doesn’t explicitly back up that claim with concrete evidence, however it uncovers how implants have the potential to deflect or curve a bullet's tract.
One of the procedures that plastic surgeons perform most frequently is breast augmentation using silicone implants, which surprisingly have saved women's lives over the years. For example, a 30 year old woman got shot and hit her bilateral breast implants. According to the report, the silicone implant was likely responsible for deflecting the bullet's trajectory and saving her life as Giancarlo McEvenue explains, “The only source of deflection is the patient’s silicone implant." That deflection is what was said to have saved the woman's life. “This implant overlies the heart and intrathoracic cavity and therefore likely saved the woman’s life.” Which again reinforces that the bullet could’ve caused a great deal of harm, but the implant alleviated some of the pressure.
The article never directly claims or states that breast implants are bulletproof, it more so goes into statistics regarding the technology behind how breast implants work and how common they are. A different article by Christopher J. Pannucci et al agrees “It would be a mistake to believe that an implant could be a substitute for a bullet-proof vest.”
So yes, the silicon breast implant did take part in saving this woman's life, but not for the reason the title claims. They are not bulletproof, but in some cases have prevented more extensive injuries due to their ability to deflect the bullet's tract.
https://journals.sagepub.com/doi/10.1177/2513826X19898821
https://www.k-online.com/en/Media_News/News/The_unexpected_benefit_of_breast_implants