In this earlier answer on dental health and hygiene in the Renaissance, I talk a little about the prescribed use of aromatic herbs as well as the links between "bad [smelling] air" and sickness.

The Trotula, a compendium of three 12th century medical texts linked to the Italian woman physician Trota, even offers a bad breath cure:

For whitening black teeth and strengthening corroded or rotted gums and for a bad-smelling mouth, this works the best. Take some each of cinnamon, clove, spikenard, mastic, frankincense, grain, wormwood, crab foot, date pits, and olives. Grind all of these and reduce them to a powder, then rub the affected places.

This sort of remedy, of course, would have been reserved to the wealthy. However, at least the idea of cleaning off teeth through rubbing and some kind of grit/exfoliant could apply more broadly.

And this fun answer on bathing and hygiene standards changing over the early modern era winds up with a...creative...remedy for the awful stink emanating from the mouth of a French royal (courtesy of everyone's favorite court gossip, Duchess of Orleans Charlotte-Elisabeth von der Pfalz):

The first Dauphin followed his father's example and took unto himself a miserable and smelly creature who was a lady-in-waiting to the old Princesse de Conti...She looked like a pug dog, and was small, with short legs, a round face, a turned-up nose, and a large mouth, filled with rotten teeth, which smelled so badly that one could smell them from the other side of the room...I believe the Dauphin took to tobacco in order not to smell the odor of her teeth.