I have a tiny black dot inside of front tooth?

Early cavity?: The inside of the upper front teeth had a small pit, or fissure that formed as the lobes of the developing tooth joined during formation. It can be a cavity that is new. Even more likely since you are the tight age, it could be a small silver filling that was placed in your childhood that you just noticed? Ask your dentist to be sure.

Unknown: The tiny black dot could be one of many things, from a stain to a cavity. Have your dentist evaluate it to make sure what it is and how to address your concern.