Tips I have learned over the years. In priority order.
Buy a sonicare toothbrush. They are supposed to be better than even Oral B because of the sound waves they produce. May seem expensive but far cheaper than almost any dental procedure. Studies have shown that electric toothbrushes clean better than manual.
Brush daily.
If you cannot brush one day at least use a flouride mouthwash.
Do not use water on your toothbrush. Something in water hinders the effectiveness of flouride.
Do not rinse your mouth with water after brushing. Leave that toothpaste on your teeth.
Buy a water pik and use it. They clean better than flossing.
I remember a 3D version of Tetris on an early IBM PC clone. Very early like 8088 or 286 PC. Don't remember the name and it was only wireframe and 1color (amber or greenscreen?) but I was very impressed with it. Seemed ahead of its time.
Looks like it will be a BROWN Christmas here this year. Which is a grim fucking reminder that we've fucked the planet and it is only going to get worse.
I agree that the situation in the article is complicated and that these homeless people were not exactly saints.
My point above is that these homeless people living in tents in an empty lot in January are worse off than the homeless people in the article that OP references. Those homeless people live in cars in a protected lot which I think is a big improvement from tent life.