There are many reasons for canker sores, some simple and some more serious. Most canker sores are brought on by stress or certain foods. If you have more than one sore or are getting them often see your dentist or physician to be evaluated for Suttons disease or Bechet's syndrome. 

You can try salt water rinses, mouthwash or any other over the counter or home remedies and they go away in seven to ten days. In our Levittown office I place a drop of debactrol on the sore and within a minute the pain is gone and you can return to your normal activity. I've been told that you can obtain the same relief with a diode laser. In any case if you get one now and then try to reduce the stress in your life. If you are constantly suffering from canker sores make an immediate appointment to rule out serious systemic problems.