Dear patient I would like to ask you few question ? Do you feel any kind of pain? If it's paining which region/side Which side of ur tooth u feel it's black marks ? Kindly recheck If itz asymptomatic/ no pain and only black mark visible on front side, of ur Tooth then u need only scaling / cleaning. And if the black mark is visible on top of your back teeth then you need dental cement feeling. And if it is symptomatic / pain then u need root canal treatments .

Black marks may be present because of n nos of reasons...Some of them are previous trauma, long intake of iron or multivitamin syrup, improper brushing etc... Without seeing you clinically it would be difficult to tell u the exact treatment plan. If u post a pic of your teeth, it would be helpful.. Thanks and Regards..

Stains on teeth maybe due to improper brushing leading to collection of deposits.