Breast implants for males
Dr. Edwards has summarized the issues excellently.
Males can get breast implants to simulate female breasts. This is most commonly performed in the process of a Transgender transformation and is freqeuntly combined with hormone therapy to promote growth of the native breast tissue as well.
Pectoral implants are a completely different matter and composed of solid silicone.
Males can have breast implants placed and the techniques are quite similar to those used in women.
Often patients like this undergo a series of other treatments and surgeries.
If you are referring to trying to feminize a man's breast, it is possible but is done in conjunction with gender reassignment and not all plastic surgeons perform this procedure. If you are referring to enhancing your chest as a more masculinizing move, there are pectoral implants that are made for men. Again, not all plastic surgeons perform this surgery so your best bet will be to call around in your local area.