2 off/on abscesses/infections above 2 diff teeth for a decade- antibiotics never help. dangers and possible health complications/damage done/next step?

Evaluation: Please be evaluated by a local endodontic specialist. If the lesions have not resolved after this much time, the teeth may need surgery to clean out the lesions or they may be deemed hopeless and extracted. Let a local dentist or endodontist advise you of what is best in your situation.

Root canal therapy: Antibiotics alone will not eliminate a dental abscess, they can only shrink in down for a short period of time. To cure the problem you must eliminate the infection that is inside the tooth. This is what a root canal procure is for. Leaving this untreated can lead to anything from loss of the tooth to fatal brain infection. Get this treated by a qualified dentist asap, don't wait any longer.

Some serious : Possible complications, including expansion abscess into sinuses or other structures, and seeding bacteria to both blood stream and brain, increasing long term chances of dementia, as well as mdr bacteria. The brain fog you mention could even be related. You should see an oral surgeon and possible infectious diseased doc. This has been going on too long with eventual severe consequences.

Next step:: It's unclear as to type of infection present, the source(s) & what treatment has already been rendered & by whom. What you describe is unfortunate, but without knowing more information, being able to examine you along with current x-rays, we can't resolve your issues. Danger is present to loss of bone, teeth & spread of infection. Consult with the most respected general dentist in your area.

See a dentist: Treating a tooth infection with antibiotics without treating the source of infection is like leaving an infected splinter and taking antibiotics. The infection may subside for a while, but because the source of infection remains, it will keep recurring. See your dentist to determine the appropriate treatment of your teeth.