Flexible belly button bars
Plastics piercing jewelry have been used for a long time for both piercings and implants. Early piercers often used it as piercing healing jewelry. The method is still in use today, but to a much smaller extent.
Plastic piercing jewelry are a light material, with an amazing resistance to the body's chemical reactions and safe against most allergies.
PTFE or Teflon was invented in 1938 and is used in the medical industry as well as for frying pans. It is biocompatible, meaning it will not cause allergies. It's a lightweight plastic, it's bendable and very stable. It's well suited for implants and piercings, specially if you want a little elasticity in the jewelry. It's also a good material to use as retainers, when you need to take out any metal jewelry, like when in surgery or when X-rayed, so that the hole won't shrink.
