Recently I had a very painful canker sore that wasn't healing by itself nor with my usual treatment (salt water rinse). My daughter Amy said that she has had good results using a cold laser (low frequency, low power laser). As usual I was very skeptical, but the pain was bad enough I decided to give it a try.
The results were not conclusive, but the sore was much better in a couple of days. I decided to do a little more research. Very little evidence seemed to be available, but I came across the following articles, which were far more credible and positive about this type of treatment:
For pain: https://www.ncbi.nlm.nih.gov/pubmed/28987080
For various skin conditions: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126803/
My conclusion is that I would try it again and I'm interested in more evidence.
One paper suggests LED light might be much better than laser for many applications, and is certainly cheaper.
Have you tried this and what are your conclusions?