[adrian_b]

I can imagine that there might exist people who cannot brush their teeth.

However, for such people the solution is not to drink fluoridated water, but to use fluoridated water to wash their mouth and then spit it.

If they cannot take water in mouth and spit it, then they certainly cannot feed themselves and they need permanent care. Whoever does that should also take care of their teeth.

Regarding money, I cannot believe that to be an obstacle. I eat relatively cheap food, because I buy only raw ingredients that I cook myself. Therefore in most days food costs me at most $5. I doubt that anyone who is really poor succeeds to spend much less for food. I wash my teeth after each meal with rather expensive tooth pastes from Colgate or Sensodyne. Even so, the daily cost for the tooth paste is at least 30 or 50 times less than the cost of food, so unless there is some remote place where the price of tooth paste is much more than 10 times more expensive than in Europe or North America, I cannot believe that being poor would prevent someone to brush their teeth. They would die of hunger much sooner than that.