797
(dnd 5e) Prove me wrong, RAW
(sh.itjust.works)
Disclaimer: this is purposefully obtuse.
Other effects in the game which explicitly state they kill you:
Shadows, succubi, massive damage, death saving throws, beholder death ray (notably not even their disintegration ray kills you), power word kill, vampires, mind flayers, night hags, drow inquisitors.
Clearly, if they intended for disintegration to kill you, they'd have said so. Since specific overrides general, and there is no general rule that disintegrated creatures are dead, I rest my case. QED.
Get the feeling it would be difficult to have a dust based strength character though. Hard to hold weapons/make attacks with them as dust.
Maybe wizard?
Two-handed weapons require two hands, and one-handed weapons require a free hand to load. But you could use a one-handed weapon that you don't have to load. Or rather, you don't even need to do that, since no weapons are listed as being one-handed.