As a general rule I will say NO, long term tinnitus cannot be cured but we can adjust to it. I can forget about miine until I read a post like yours; then I hear it loud and clear!
SHORT term tinnitus caused by a large dose of aspirin or other analgesics, an episode of hypertension, a cold or ear inflammation, or "ringing" caused by exposure to loud sound usually DOES go away quickly.
But if you've had it for months or years it is likely yours to keep.
I'm sure there are cases though where this isn't true.