Teeth can need work from physical trauma, too. Getting hit in the head while hunting or fighting or just hiking might cause a cracked tooth, which can be deadly in the absence of dental care. Or just while eating, sometimes a stray rock or bone fragment or shell might cause an issue.

Lots of other species can regrow teeth in adulthood, even a handful of other mammals. All sorts of animals can have tooth problems in the wild, so I wouldn’t assume that prehistoric humans were exempt from that general danger.