Yep you can get a tooth same way as blood in EtR, but players have so many more things they need to work on, that in practice, teeth are pretty rare to get from spending successes. Also because of the number of abilities that take teeth, rerolling is a second option that players will fall back on in struggles. (its much more efficient to use Curse for example than using teeth to reroll)
Happy you like it though! I appreciate the kind words :D