How long will you need the braces for? and how long have you had them? I can see contact being so heavy that the braces will break, although there is always someone who hits harder than they should.
Get the ShockDoctor boil and bite so it covers your braces, and they do a double shield if you need the bottom row covered also.
I say go for it and drill technique, that way you're learning but there's no risk of your braces breaking.
Take into account, if the braces are on for a year, or more, then that is a lot of time to just be drilling technique and not advancing to sparring. Only so much technique you can learn in that time without being allowed to put it into practice.
VIPFFL: Miesha Tate//Ronda Rousey//Mike Pyle//Ian McCall//Rick Hawn