google my friend.. its exactly what it sounds like. the natives used to make teas, pastes, extractions from it for toothpain among other things.. but usually i just go the easy way an lightly chew on the little pebbles of bark.. like 2 mins n its all numb n shyt. lol. if youve got a cavity the bark pieces become saturated from the saliva an become somewhat mailable, you can shove a piece in the cavity n just replace every couple hours as need be.. works like a charm no matter how you choose to use it.