The truth is that tooth decay is a relatively new phenomenon. Until the rise of agriculture roughly 10,000 years ago, THERE WAS NO TOOTH DECAY IN HUMANS. Let that sink in for a moment. Humanity is 2,500,000 years old. For the first 2,490,000 years no one ever had a cavity. If we understand that tooth decay started when people started farming instead of hunting and gathering for a living clearly you realize that tooth decay is a disease or mismatch between what you are eating and what your body expects you to eat. If we examine the past as prologue it becomes clear that the path to proper health starts in the mouth and the answers are so simple that not only did a Cave Man do it. They perfected it.