Nickel is added to the metal in braces (and crowns; stainless and porcelain over metal) so they don't rust. It is a known cancer causing agent, added to our government's list a few years ago. They are still able to put it in people's mouths though, along with many other toxic things. I suggest you get invisalign. Nothing is toxic-free, but it is better than nickel.
Irritating Dental Work: Another Leading Cause of Oral Cancer
