A dentist discovers a machine that allows her to travel back in time and go to Europe in 1500 AD. The machine allows her to go back in time only once (and never to return). These are harsh conditions, of course, but our dentist is a perfectly altruistic person that only cares about the greatest good she can do. She figures that, while there are many other professionals with the same medical knowledge and skills in her current time (= 2017 AD), in 1500 her knowledge and thus her potential to do good would be exceedingly greater. Or would it?
There is only one problem. Going back in time she can take nothing with her: no medication (pain killers, anaesthetics), no tools (dental drills, dental forceps, headlight, ...) etc. Only the knowledge and skills she has acquired in modern times remain.
Despite these difficulties, our altruistic dentist is determined to go back and help as many people as best as she can. Only one question remains (for you to solve): How is she going to do it?
Please assume that our dentist is a bit myopic and does not think or care about unintended consequences her actions will have in the long-run (so no time traveller's paradox or anything related). Her only metric is: How she can relieve as many people as possible from their pain and improve their (dental) health.