This canker sore thing is not working?!

The best thing I've ever found for canker sores is to rinse my mouth with peroxide. It might sound weird if you've never done it, but if you check the bottle it says it can be used as an oral rinse. Also, toothpaste with peroxide and baking soda does wonders. Usually this clears up my canker sores within a day. Hope that helps -- the stupid things are so painful and annoying!

It could take several days, especially if there is still constant pressure on the sore. If you have braces, cover them with orthodontic wax where the brackets are rubbing. Otherwise, try not to pick at or nibble at your canker sore and avoid salty and sour foods until it goes away.