Sesame seeds are great in many ways: use them for seasoning your salad or removing tartar. They act as a natural scrub, and polish and clean the teeth at the same time.
Take a full tablespoon of seeds into your mouth and chew well. You need to try to create a kind of paste and not swallow it in the process. Then brush your teeth with this paste and a dry toothbrush. Do this twice a week.