My own very limited guess is that it could be a cavitation of the jawbone.
You are probably right. Based on this scientist who claims tests show 90% of root canals are cavatations. http://tinyurl.com/jnh5olw
Your problem is you aren't going to get rid of the problems you can see in your mouth until the bone infection below the gum is cleaned out and treated to get rid if the infection.
From personal experience, a dental surgeon will have to cut the gum open to get to the jaw bone. my jaw bone was like mush that had to be scraped clean and treated so new bone would grow.
I would suggest seeing a dental surgeon of the holistic type to do it.