Hi. A safe natural way is fresh strawberries! hold the juice in your mouth for 5 minutes...spit out! Tasty!

Also, a dentist created plaque/tartar removal, naturally, with grapefruit extract, grape seed extract, peppermint oil, thyme oil, neem oil. All natural ingredients...originally meant for pets. Yet it is now made for people.
It is prepared and sold on the retail market under name of "Plaque Attack" or "Petzlife".

You can look it up on Youtube. I have yet to try it. Check it out. Watch the video.