I have black dot or mark in 3rd lower teeth what to do?

See a dentist: Black dot could be a stain or a cavity. The dentist can evaluate and figure out which one that is and treat it if needed.

See your dentist: Why don't youngo to your dentist and have him check it out . It might be decay or a stained enamel pit. But your will not know until it is checked out by a dentist.

See a dentist: A black dot probably is a sign of a cavity. See a dentist to have the teeth examined.

Decay/stain: Likely decay or stain. If decay, wisdom tooth is often extracted rather than filled. If so, see wisdom tooth expert. For best results with wisdom teeth, make sure you are evaluated and treated by a board certified oral & maxillofacial surgeon.