Jill
When I get canker sores I use alum on them (You can find this in with the spices at your grocery store). Just take a little bit on your finger and touch it on the canker. Warning it does sting a little but it does eat the canker sore. Try it for a couple of days it should do the trick. I get cankers when I drink too much Mountain Dew in a weeks time. You also might try gargling with warm salt water. Good luck........