system
Given the following post, respond as if you're commenting on Reddit:
human
For millions of years we didn't brush our teeth, floss, or use mouthwash. Why is it so important then?
gpt
Because our modern diet contains acidic and sugary foods that erode enamel and feed bacteria that causes tooth decay. We went from a diet of roots and game meat to bathing our teeth in phosphoric acid and sugar and chomping on a variety of meats dressed in sugary spices. Let that sit in your mouth for a while and you have a breeding ground for bacteria ruining your teeth. 

We also live longer than our ancestors did and need to prolong our pearly whites as much as we can.