since your EC appeared right after teeth cleaning, it may be a case of contaminated dental instruments. Dental instruments do grow lots of bacteria and mold on them. That is why it is important for dentists to make sure the instruments are sanitized.
JSL, I thought you wrote that you were using Listerine mouthwash because your dentist recommended it? Since you wrote that it tingled or I forgot the exact word you used, but that is the feeling brought on by alcohol. Mouthwash with alcohol dries the mouth/lips and causes bad breath. You could try Listerine Zero since it has zero alcohol in it.