"If you think you're having problems in life, imagine you're in the dentist's chair getting a root canal ... and the power goes out"
-- Mark Curry ... minutes after it actually HAPPENED to him yesterday.
With a half-numbed face and a mouth full of cotton balls ... the former "Hangin' with Mr. Cooper" star was standing outside of his dentist's office in Beverly Hills moments after the building lost power.
Despite the circumstances, Curry was crackin' jokes about the situation ... telling us, "My dentist had a flashlight on the top of his head and a drill he brought from home."
The worst part -- Curry says he has to COME BACK to the office so his dentist can go back inside of his mouth to finish the procedure. Suuuuuuuucks.