I am wondering when was it realised that humans need to regularly brush their teeth in order to keep a decent dentition. My few research led my to believe that the Greeks were already doing so but was it a popular thing?
Here you go:
http://www.reddit.com/r/AskHistorians/comments/1bii71/when_and_how_did_the_concept_of_teethbrushing/
http://www.reddit.com/r/AskHistorians/comments/twy3x/when_did_people_start_brushing_their_teeth/
Also, see this section in the FAQ: http://www.reddit.com/r/AskHistorians/wiki/health#wiki_how_did_people_in_history_clean_their_teeth.3F
I don't know if your specific question is answered, but look through those and see if it helps! I found those by searching "brushing teeth" in the search box. Enjoy!