We are discussing if breast implants need to be replaced every so often. There are two types of breast implants. There are silicone breast implants and there are saline breast implants. In a saline breast implant, there's a silicone shell and it's filled with saline which is, for all indents and purposes, water.
In a silicone breast implant, there's a silicone shell and it's filled with a form of silicone that is almost similar to a gummy bear consistency. The saline implants, in theory, are supposed to last around ten years.
So, if you have a saline breast augmentation, after about ten years, there's a chance that they could deflate which is not dangerous, but it would mean that they would need to be replaced. So, back in the 80's and 90's, silicone implants has a much thinner shell and the quality was much poorer. Therefore, old silicone implants, that were put in in the 80's and 90's, those implants might need to be replaced because the shells were not as thick and the quality simply wasn't as good.
Today, manufacturers make silicone implants that have a thicker shell and a much higher quality, So breast implants made today, manufacturers actually give a lifetime warranty and the implants, the silicone implants, that are used today should ask for a patient's life. That being said, there's always the chance that some sort of re-operation would be necessary, but it's very unlikely that that would be because of the structural integrity of the implant due to the high quality of breasts implants today.