Takes awhile Katie....you should see me when I have a morning appointment for a filling.....I have not had my coffee yet and I am dying for a cup....so I wait until after my appointment for about an hour after the filling.......I need coffee bad so I get some and you should see me trying to drink hot coffee with half a numb mouth! Its all running down my chin and face!!! Gotta have my coffee....so now I wait a few hours first...as hard as that is!