What contribution did Leonardo da Vinci make to dentristy?

Well, it seems a tenuous link to me, but many of da Vinci's engineering schematics pre-date the mechanisms used in today's electric toothbrushes. I wouldn't have believed it either but here is the link (from Cornell, no less): a href="http://kmoddl.library.cornell.edu/leonardo/" rel="nofollow"http://kmoddl.library.cornell.edu/leonar…/a