Burning Mouth Syndrone

I have had this on and off for 10 months. The first time, was after getting off of pain meds. I was off for 3 months and my mouth started to tingle in my lower guns and the tip of my tongue had a burn feeling to it. Ive always had good dental hygene and get my teeth scaled and cleaned. It feels like gingivitis, but it's not. An oral  specialist dentist cannot find what's wrong. I dont clench my teeth in anyway. They dont even match up for me to try to clench. Well, after three weeks of intolerable pain, I took one of my pain meds and the pain went away. So, that is how I got back on pain meds for 9 months. Now that I am again tapering, the sensations in the gums and tongue have once again begun. I read about a vitamin callled, Alpha Lipoic Acid, 60mgs, that might help. Anyone ever heard of this? I also use sensadyne but it doesnt help. Ive brushed my teeth for years with this due to sensitive teeth, but for this particular situation, it isnot helping. Any ideas would be welcome. thanks....