Are inert substances that are harmless to the human body. If we really want to discuss the pros and cons, there are micropores on the expansion body, and there is no envelope phenomenon, so there is no sense of outline. However, the silicone prosthesis is difficult to take out for a long time because of the growth of its own tissue, and it will have a slight sense of outline after implantation. However, if the plastic surgeon passes the technical test (but many plastic surgeons will directly implant the nasal prosthesis without carving, so it is easy to have a nose in the air and a Roman nose! Measuring doctors and plastic surgery institutions is also one of the key points), and this problem can also be avoided. Moreover, silica gel has no micropores and can not be combined with its own tissue, so it can be taken out at any time.