Canker Sores, technically known as Aphthous Ulcers, is an autoimmune condition with poorly understood triggers. Potential trigger foods may include nuts, chocolate or acidic foods. They can erupt from trauma such as a cheek bite or even from a toothbrush. Sodium Lauryl Sulfate is an ingredient found in most toothpaste and mouth washes that can trigger sores. Consider using Biotene toothpaste or Rembrandt for canker sore sufferers. Also, consider regular use of an antimicrobial mouthrise such as chlorhexidine or Listerine to prevent an eruption.
In the event you find yourself with a canker sore, topical products are available over the counter that work by coating the lesion to shrink or numb it or both. To coat and numb, try Orabase B, Zilactin B, or Kanka. To coat the lession only, try Orabase Soothe-n-Seal, Liquid Carafate, Ora 5, Benadryl/Kaopectate or Aphthasol.
Medications are available by prescription. Such medications reverse the autoimmunie process. Ask your dentist or doctor about these if cankers persist.