A tooth with a black spot caused by caries needs a filling, while a tooth with a black spot caused by other reasons does not need a filling. A black spot on the tooth can be considered caries, a decayed tooth slowly develops into a cavity, which looks like a small black spot. At this point, timely treatment is needed, usually in the form of a filling, which requires grinding away all the black decayed material on the tooth, and then filling it with resin or other materials to make the tooth complete again. Teeth have a black spot may also be caused by other reasons, such as pigmentation, etc., mostly caused by daily diet, improper cleaning, etc., at this time the teeth just look darker, but the teeth are healthy, so there is no need for fillings. It is recommended to go to the hospital stomatology department first, to understand the cause and then consider whether to fill the tooth.