Unhulled sesame seeds has calcium in it
Ayurveda knows this which is why we like to swish sesame oil in our mouths as a daily practise. For some the thick oil makes them feel gross. Another way is after you brush your teeth you can put a little unrefined sesame oil on your finger and rub it on your gums and teeth. Then you can swish a little water to take the excess away.
I personally healed all sorts of gum and teeth issues from this practise and I come from a long line of dental fillings. Sesame also seems to have a nice cleaning effect to it - it will naturally whiten your teeth if done regularly without the harsh chemicals.
Chewing a handful of sesame seeds is good for the bones and teeth and they say that chewing black sesame seeds daily will bring back the dark colour in your hair. This I'm experimenting with at the moment!