My daughter has the exact same situation. The black stain is on her every single tooth and she resists to let me brush her teeth too. Whenever she sees me holding a toothbrush, she runs away immediately. It looks kind of gross when she laughs as you can see the black stains so easily. I am thinking to take her to dentist too. How did you make her open her mouth in front of the dentist? Which dentist did you go? Can you give me the information of the dentist? Thank you!