I used to get mouth ulcers fairly regularly. My dentist recommended Amosan powder which fixed them up in 24-48 hours if I caught them early, rather than days with other treatments. I have not had one ulcer since I gave up smoking nearly 3 years ago.
I’m glad to see that it worked for you. I have been an evangelist for SLS free toothpastes for years and always recommend them when the question comes up on the boards. There are two brands I am aware of. One is Biotene and the other, which I prefer, is made by Rembrandt.
Haj
I tried the Rembrandt, but found the consistency too thin in my mouth; it was like trying to brush with milk. I use JASON’s stuff, which is expensive but pretty tasty if you’re into the natural style (compare to Tom’s). And like I said, no more canker sores. As pricey as JASON is, I’d pay four times as much to continue being free of the suffering brought on my the sores. Shudder…
this may or may not be useful to you but I have found that one thing that will almost always give me a canker sore is anything with sorbitol. Wrigleys brand chewing gums in particular will give me a canker within hours.
I used to get a canker sore in my mouth almost weekly right throughout my teens years, before I picked up somewhere that citric fruit can cause them. I used to eat oranges every day. I cut them from my diet, and it produced instant results - I no longer get the sores.
I’ll take the salt-water step further. Mine are gone within 24 hours. Prepare yourself, this hurts like a sumbitch.
Put salt directly on it if you can reach it. The pain will send you through the roof, just leave it there as long as you can take. The more often you can do this the faster it’ll go away.
I have used Rembrandt with good success also.
Rembrandt seems kinda expensive though, I had read that Toms of Maine does contain SLS, but in lower amounts. I have been using Toms for awhile now with good results.
FWIW, I’m not sure that problem is “allergies” to SLS per se. SLS is a detergent which can irritate tissue ( especially tissue that already has nicks or cuts).
Ahhh cite to above post found here
Another vote here for Rembrandt’s toothpaste. I used to be miserable with all the cankers I would get, and now I haven’t had them in something like four months.
Are canker sores the same as mouth ulcers? They are damn painful and can take ages to heal.
I went to one website where people vote for treatments that heal, and those that help the pain, and salt solution was the overwhelming winner in both categories. I find a solution of myrhh, swilled round, can help. I bought some herbal stuff that contained rhubarb, but it was crap.
As I understand it, canker sores start off as a blister in your mouth. They can develop from something rubbing (like a tooth or badly fitted denture) but can also just appear. Mine tend to appear when my sleep is messed up, and if I don’t then get proper sleep, they take forever to heal.
I have one currently, and am doing some experimentation on it, after finding out that after I stretched my mouth about to look at it in a mirror, it hurt less. I don’t know whether this was because of the strong light on it, exposure to air, or (less likely as it wasn’t that hot) the heat from the lamp. I tried exposing them to direct very bright sunlight this morning for 30 seconds or so, but it wasn’t a noticeable improvement on the lamp (which is just a little halogen bedside light).
IIRC some nasty ulcerous aliens in an episode of Star Trek could only be got rid of by light. Maybe that’s what they are… 
I’m another person who has benefitted tremendously from the Rembrandt toothpaste.
Another trigger for me is food with monosodium glutamate (MSG) in it. This is in a lot of things, so I really have to read labels to avoid it. It is not an allergen, but from what I understand the way it “enhances flavor” is by stimulating (in my case, irritating) the lining of the mouth. Flavored potato chips, for example, were a major cause, since they were both crunchy and contained MSG in the flavoring.
I haven’t seen MSG mentioned other places in connection w/ canker sores, and the Internet has sites blaming MSG for every possible ill. I’m just recounting my personal experience in case it helps a fellow Doper.
istara, I have also noticed that when I stretch my lip to examine a canker that the pain goes away momentarily. My theory is that when pulling/stretching the lip out, the saliva around the area simply evaporates quickly. Since saliva seems to irritate canker sores (ie, it hurts like hell if you hit it with your tongue), the quick evaporation removes the agent of discomfort.
Does Pepsodent Original have SLS? That is what I have used since I stopped using kid’s toothpaste years ago. I might switch to Rembrandt if Pepsodent does.
Does sugar help cause them or make them worse?
Looks like a lot of people here have this problem.