Random observation -- my family seems to have a gene that makes us basically immune from cavities. My father has, to my knowledge, never had a cavity, despite being born in the 1930's, when health care, hygiene and regular dentist check-ups were not what they are today.<p>I've gone months without brushing my teeth. Been to the dentist twice in the last 10 years - no cavities. (Of course, starting in college I realized I should probably brush in the mornings for breath reasons...)<p>I've often wondered if some clever bio hacker could figure out what protein my genes are telling me to include in my saliva and reverse engineer it. Perhaps these guys did something similar.