Hi to all that helped me with my canker sore dilemma back about 4 months ago. Well, I thought I should come back and report what I found and how it has helped my husband. I did some research and found out that some people have a problem with the sodium laurel sulfate that is in toothpaste. My husband was skeptical that such a simple solution would help him. Well, I didn't want to post until some time had gone by and now here it is, about 4 months and my husband is reporting that he is amazed that he has not had one canker sore in those 4 months. The only thing that he is doing differently is that he is using a toothpaste that does not contain SLS. We were lucky to find it at our local grocery store. The one we are using is Biotene. I just thought that I owed it to anyone that comes here and reads these forums to report this remarkable solution. My husband is amazed cuz he says he would normally get a canker sore at least once or twice a month. Good luck to anyone else with this same problem and please don't hesitate to write me if want more info. It's pretty simple though. My thought is that some people's Ph balance must be different and when they bite their lip or tongue, they just cannot deal with the SLS the way the rest of us do and a canker sore erupts. Eliminate the SLS from toothpaste use and eliminate the canker sore problem. Again, my theory based on what I have just observed.