Controlling bacterial spread to prevent diseases has been a hallmark of modern living. It is why we wash our hands, sterilize medical instruments, regulate dining facilities and have health standards for everything from drinking water quality to how we bury our deceased. These are standards that differentiate our lives from those of hundreds of years ago.
We recognize polluted bodies of water as health hazards. We would be concerned about living too close to a garbage dump, especially if it were near a life supporting body of water. Our mouths are breeding grounds for bacteria. The warm, moist, dark area is perfect for allowing organisms to grow. Allowing the bacteria that make up gum disease to live there is no different than allowing wastes to rot in your kitchen garbage.
Establishing higher standards of oral hygiene will be one thing that will make for a healthier population of the future.