The fact that tooth decay risk is greatly elevated in diabetics is proof that tooth decay is largely a systemic disease, not something that is caused just by a few specific species of bacteria as mainstream dentistry falsely believes. It's interesting to note that the Japanese brush more frantically than most other industrialized countries and they have more tooth decay not less. We've been lied to. Manmade oral hygeine does not prevent tooth decay. It never has and never will.