Starchy food led to rotten teeth in ancient hunter-gatherers: https://www.ox.ac.uk/news/2014-01-07-starchy-food-led-rotten-teeth-ancient-hunter-gatherers https

Starchy food led to rotten teeth in ancient hunter-gatherers: https://www.ox.ac.uk/news/2014-01-07-starchy-food-led-rotten-teeth-ancient-hunter-gatherers https://www.ox.ac.uk/news/2014-01-07-starchy-food-led-rotten... But I think the more common prehistoric tooth problem was severe wear from using the teeth to process things like fibers and hides.