The only times I've had trouble with my teeth is when I was digging into the maple syrup too often and too much.
Even the dentist attributed it to that.
Perfectly good teeth going bad and definitely not from any kind of deficient or poisoned diet.
He said the Sugar in the syrup becoming acidic on the surface of the tooth burns the enamel. - not good.
I've stayed away from the syrup, since I tend to go overboard, and have had no trouble since.