Bearded dragons are born with their chompers ! However, if *certain* front teeth they have fall out, they have the ability to regrow (only those specific ones).
Beardies have teeth from birth, though sometimes they can be hard to see because they are so small. They don't have a "baby" set and "adult" set of teeth and don't naturally lose them and grow a new set. Some can regrow if lost and some can't though.