It's possible for it to lead to increased clenching/grinding of teeth.
With that said....a decent diet and doing all the things you're supposed to be doing anyway in terms of oral hygiene and you ought to be fine. It's not a "you're going to ruin your mouth", it's a "pay more attention to this".
Been taking Adderall XR for >10 years, no cavities or other dental concerns personally speaking.
it does dry out your oral/nasal cavity. It can cause your body to produce mucus to compensate. I commonly feel like swallowing is slow as if there is a thin layer of mucus lining my throat. Even had yellow mucus drip out of my nose as if it were a nose bleed (happened 3-4 occasions), which comes from having a sinus infection.
This is one of the reasons I switch to micro-dosing on an empty stomach and supplementing with coffee to limit exposure to amphetamines.