I've never looked into the facts, but anecdotally I've known of two close friends who never (and I mean never - not an observation, but an admission) brushed th

I've never looked into the facts, but anecdotally I've known of two close friends who never (and I mean never - not an observation, but an admission) brushed their teeth and never had one solitary cavity. They ate pretty normal American diets (meat, sugar, carbs, soda, coffee, but nothing in excess). Additionally, I've heard this same second-hand anecdote from others multiple times in my life.