Receding Gum Line - what to do?

I got into oil pulling about 5 months ago because of gingivitis that had turned to periodontitis according to my dentist. Before that, I have had a cleaning every three months, brushed at least twice a day with a special fluoride toothpaste to strengthen my teeth, had changed to the Sonicare electric toothbrush for better cleaning a few years ago, flossed, and used an Ayurvedic mouthwash. Almost no improvement! I grind my teeth at night, which could be a reason for the inflammation.
I started OP after being told I need flap surgery, and after 2 months of diligent OP every morning, my dentist noticed an improvement. Since, I stopped using the fluoride toothpaste, and started to feel better, saw my gums improve further; I stopped using the Sonicare when I noticed it hurt me while brushing my teeth and returned to a soft toothbrush using Weleda's herbal toothpastes.
Last week, I bought an herbal gum tonic, and massaged it into my gums with additional progress in form of natural color, and gums/teeth feeling more 'connected'. Except for one area, where I see no progress, and since using the gum tonic a worsening of the symptoms. My gum line around that tooth has receded up to about 2mm since using the tonic. Sure, it doesn't look as inflamed anymore, but to me that seems because it has disappeared. Sorry for the long introduction to my question now: Does anybody know what could be going on? Because it feels like the rest of my mouth does benefit from the tonic.
I read a lot here around additional possibilities and am about to try Colloidal Silver , did some Iodine swishing today (using Liquid Iodine Forte from Biotics Research that I have been using for a different issue), read about Dr. Schulze 's gum tonic, and on applying a comfrey and cayenne pepper poultice to help restore tissue, and wonder about the Utopia's Colloidal Silver with aloe vera to swish with - but I am a bit at wit's end as to what the best option is at this point, not to worsen that one spot and not to go crazy with all those possibilities.
My regular oil for OP is unrefined, organic sesame, which I absolutely love; I tried walnut today for the first time thinking it might aid the healing process due to the omega-3s etc - it was green when I spit it out. Argh! :-)
Thanks for any suggestion! Tweet