system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Without proper dental care, how did people thousands and hundreds of thousands of years ago keep their teeth from completely rotting out?
gpt
By not eating a modern diet of refined sugar.  Much of the tooth decay seen in modern people is the result of refined sugars which encourages more bacterial growth in the mouth than would have been found in ancient times.

Not saying they didn't have tooth decay but they didn't have it to the extent that we would if we stopped brushing our teeth.  Our teeth would very quickly rot away.