Teeth suddenly have black spots may be long-term smoking, poor hygiene habits and other physiological factors, or may be due to caries and other diseases, the patient can take general measures for the cause of the disease, medication, surgical treatment, and so on. 1. Physiological factors: If long-term smoking, not timely cleaning oral hygiene, may lead to pigment accumulation, there will be a sudden black spot on the teeth. If there are no other uncomfortable symptoms, it is a normal phenomenon. In daily life, you need to control the frequency of smoking, pay attention to oral hygiene, if necessary, can be scaling. 2. Caries: Sudden black spots on teeth are also considered to be caused by caries. Surgical treatment can be taken, such as silver amalgam filling, composite resin direct bonding restoration, inlay restoration and so on. There are many reasons that lead to the emergence of teeth suddenly have black spots, it is recommended that patients go to the regular hospital, relevant examinations, so as to clarify the cause of the disease.