The causes of blackening teeth include consuming certain drinks, such as coffee, cola and wine, as well as certain fruits and vegetables, such as apples and potatoes. Poor dental hygiene, diseases that affect the enamel, head and neck radiation, and some medications, such as tetracycline and doxycycline, also darken teeth in children under 8 years of age. Additionally, genetics, excessive fluorides and trauma also discolor teeth, according to MedicineNet.
Dental materials, such as amalgam restorations, especially those containing silver-sulfide, darken teeth to a gray-black color. The outer layer of the enamel wears with age, revealing dentin that is naturally yellow. Individuals can better maintain white teeth color by avoiding rinses and toothpaste with excess fluoride. Trauma can affect enamel formation in children. People can also prevent teeth from turning black by cutting back on coffee and quitting smoking, states MedicineNet.
People should brush their teeth and floss regularly. Additionally, they should visit a dental hygienist once every six months, and they should consult with a dentist if their teeth darken despite good oral hygiene to ascertain the cause. Treatment options for darkening teeth include bonding, veneers and using whitening agents, according to MedicineNet.
Excessive intake of fluoride causes fluorosis. This condition darkens tooth color, and it also causes surface irregularities and noticeable pits. Excessive intake of fluoride in childhood also darkens teeth, as reported by WebMD.