Can listerine cool mint cause canker sores?

It can: Many people have reactions to the ingredients in mouth rinses. Just do a controlled test on your own by trying different rinses. Also look for a non- alcohol rinse.

Probably not: It is unlikely the mouth wash caused the sores, but it can definitely make them more uncomfortable. Avoid acidic and spicy foods and drinks. Canker sores are caused by a combination of factors including stress, poor diet, etc in combination with the herpes simplex virus which is always present in your mouth. If pain is extreme your dentist can apply topical agents that will shorten the time.