Can't fix normal bake problem with bias and distance

I´ve got some trouble with normal maps.
Baking from a multiRes to a low poly model.
I’m modeling teeth here, and in the middle of almost every teeth there seems to be an anomaly.
I had some error with opposite colors, but I could manage them by adapting the bias and distance.
How can I get rid of these last errors?
Thnx
Ethan_145Teethbake.blend (2.92 MB)