You mean in terms of creating some stimulating mental activity ? It is possible but it is hard to be sure without doing further research.
It might be a combination of lots of different things that relate to brushing your teeth or itmight be that whatever underlying processes cause dementia, also make your teeth fall out!
Of course, only research can conclude. Sometimes, I wonder taking out the wisdom tooth make one lose some wisdom. Perhaps, all teeth are some bit of wisdom. hmm....