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My Canker Sores Hurt! What Can I Do About Them?

Canker sores are referred to in the trade as “recurrent apthous ulcers” (RAU).  “Apthae” is a fancy Latin term that mans small little ulcers. So when you translate the fancy medical name into everyday English, it means recurrent little ulcers x2!!!!

For some folks, canker sores are truly that annoying!

Cankers are different than cold sores which are caused by the Herpes virus. They are frequently confused;  it can be hard to tell the two apart. And there are many times where both types of sores do not resemble the picture in the book. Generally, both lesions will get better over a one to two week period. (if this is not the case, be sure to call your dentist)

So let’s assume that you have canker sores: you generally will see an ulcerated area (whitish, filmy center) surrounded by a pink ring – it looks a little like a moon crater.  Their cause is variable, but sometimes we can trace it down to acid (ie. citrus fruits or beverages), toothpaste (contains sodium lauryl sufate detergent), stress (which causes everything under the sun right?), allergies, acid reflux – “Gee. . . should I go on?”

The real kicker is, once you have one, you think back and you say, “Darn, I shouldn’t have had that orange – it gave me a canker sore.” So now, what do you do?


There are a ton of remedies on the drugstore shelf – but there are some common elements to them:


FIRST IS A COVERING AGENT (which basically forms a thin film over the sore like a band-aid): pectin, Hydroxypropyl Cellulose, PolyvinylpyrrolidonePVP , Maltodextrin , Cellulose Gum, methacrylate co-polymer would be typical ingredients.

THEN SOMETHING TO NUMB IT: benzocaine, phenol, menthol

AN ANTI-INFLAMMATORY AGENT; Generallyonly seen in prescription formulas.

A DISINFECTANT: Cetyl Pyridinium, benzyl alcohol, Benzalkonium Chloride

AND OFTEN SOME MUMBO-JUMBO:  boric acid, PEG, Propylene Glycol , Salicylic Acid , Tannic Acid, Disodium Edetate ,  Sodium Hyaluronate (Hyaluronic Acid) , Glycyrrhetinic Acid , Aloe Vera

The acids cause a small ‘burn’ to the top of the lesion making a surface covering of dehydrated, less sensitive skin cells. Aloe Vera is supposedly soothing. Many of the other ingredients are merely in there to act as preservatives and make the concoction in paste form that will stay fresh on the store shelf. The rest of the mumbo-jumbo rarely makes a difference.

Bottom line here:

Since we don’t really know the real cause of canker sores, we don’t really know what mumbo-jumbo is best to treat it! And because we don’t know your exact chemistry, Orabase may work for you, but not for me. So buy an over-the-counter remedy and try it.  Since most canker sores will go away on their own, you can put anything on them and they will eventually go away.

If you have a canker sore that isn’t going away, it may not be a canker sore. Or, you may need some prescription medication. A good example of this is in chemotherapy patients. Chemo drugs are well-known for causing ulcers in the mouth. Frequently, we’ll prescribe a “miracle mouthwash”. It’s a cute term for a concoction that contains antihistamine (like Benadryl); an anti-acid (like Maalox); some topical novocaine, sometimes an antibiotic (like tetracycline) and sometimes an anti-fungal (nystatin) and sometimes a steroid (cortisone). It’s the doctor’s version of “mumbo-jumbo” ingredients’




  1.   Try an OTC remedy. If it works, use it.
  2.    At home, I might apply a little Oragel or Anbesol (topical novocaine) followed be Maalox (or similar antacid)
  3.    I would switch toothpastes – Sensodyne Pro-Enamel or Rembrandt SLS free and see if that helps
  4.   I would change toothbrushes.
  5.   I would make sure that my diet was less acidic in the short-term: avoid citrus, tomatoes and vinegar/salad dressing
  6.   If it’s not going away, call your dentist – this may not be a canker sore!


If there was a good cure, then all the remedies would have the same ingredients. But, there isn’t a good cure and so, you see a lot of” mumbo-jumbo.”  It makes us feel like we are doing something. And it’s funny, we see this same pattern in many other areas of medicine, even in this day and age.


Dr. Rick Liftig

Disclaimer: The information contained on Dr. Liftig’s website is meant to provide general information about dentistry. The information contained within this website is not intended to provide medical or dental advice, and should not be used as a substitute for medical and dental advice.  Consult your dentist or physician for your specific condition.  Dr. Liftig accepts no liability for the information provided pertaining to treatment.





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