My ten years old daughter has got a persistent brown teeth.after brushing it clears off, but got brown again by the end of the day.what is wrong?

Brown teeth: When was the last time your daughter seen a dentist for cleaning, is she drinking chocolate milk or eating chocolate cake , candy , these tends to stain teeth , have the dentist explain the reason , hard for any one of us to tell what's the cause

See a dentist: Even with good brushing, a sticky layer can remain on the teeth. It is called a pellicle a can be removed by a hygienist or dentist.