Christy,
I think the gum or resin you are thinking of is Peelu.  They sell peelu
tooth powder, tooth paste, and gum in health food stores.  The gum looks
pretty "techno"---not something you could gather in the wild or make in your
own kitchen, but it does contain some extract from the peelu bark as I
recall.  The natives who use peelu chew on these stick like things and that
cleans their teeth.  The tooth powder looks like sawdust and tastes no
better; the tooth paste taste minty and looks like tooth paste.  I tried the
gum many, many years ago (maybe 14 or more ??) it tasted sweet briefly, then
bland.  It was supposed to clean the teeth if you were away from facilities
for that.

Rachel