Alrighty then. Debunking 101:
Look up the history of oral hygiene in the US, particularly dentistry.
If this were remotely accurate in hypothesis, those who reached their senior years a century or 2 (or 3 or more) ago would all have been afflicted. “Senior” back then being 50 or 60, with correspondingly-horrible oral health. Dementia should have been eradicated with the evolution of oral hygiene in the 20th century.
Not.
It’s just another “miracle cure”...some researcher pining for grants. More BS.
Far from definitive.
Part of the hypothesis is a long latency, time to develop.
People just died before symptoms became obvious.
Even today, only a small number show the symptoms compared to the 1/3 that have the gum disease.