1) Is it true that whitening toothpaste can eat away at the glue that's used to bond the braces to your teeth?
2) It's said that if you use whitening toothpaste with braces and have your braces taken off it will leave stains or blotches. If whitening toothpaste can whiten your teeth with braces on, why can't it whiten the stains and blotches from the spots that the braces were covering? Isn't it logical that those spots will catch up with the rest of your teeth?
The reason why you should not use any bleaching materials while you are on orthodontic treament is:
Due to inevitable poor oral hygiene while you are on braces your enamel is weaker. This is why it is recommended to get a whitening treatment at least 2 months after you remove your braces.
Your question is answered here
How can i whiten my teeth if i am wearing orthodontic braces?
You should always concern a dentist before using any whitening toothpaste.We must take care of our teeth and visit dental care regularly. the dental care provides us various treatment like whitening,straightening white filling etc. so if we face any sort of problems we must attend the dentist immediately before is turns to a major problem.