Answer:
Well for me
It will reduce the risk
Then sensitisation programs should be conducted to enlighten people to go for test and only then can it be eradicated
The brown stuff is called plaque. This forms on your teeth when you eat and its something you can't get rid of. There is tooth paste that can help maintain it.
Always think better. For example think of it this way, you may not be alive tomorrow, appreciate what you have.
Also you can just do what you want, once you die, you cant do the things you wanted.