One of the main causes of tooth discolouration is consuming tobacco products and chromogenic foods and drinks (food and beverages that have the ability to produce a staining effect on teeth).
Coffee, tea, cola, red wine and certain fruits and vegetables (apples and potatoes for example) are all chromogenic agents and can stain your teeth.
The cumulative effect of the use of tobacco products such as cigarettes, cigars, pipes and chewing tobacco can cause tooth staining.
The severity of the staining in smokers depends on the duration and frequency of the habit.
Tooth discolouration can also be caused by poor dental hygiene.
Inadequate brushing and flossing to remove plaque and stain-producing substances, such as coffee and tobacco, can cause tooth discolouration.
Several diseases that affect enamel (the hard surface of the teeth) and dentin (the material under the enamel) can lead to tooth discolouration.
In addition, treatments for certain conditions, such as head and neck radiation and chemotherapy, can affect tooth colour.
Some infections in pregnant mothers can also cause tooth discolouration in the infant by affecting enamel development.
Medications are another cause of tooth discolouration.
Mouth washes containing chlorohexidine and cetylpyridinium chloride, antihistamines, antipsychotic drugs and antihypertensive medications are known to cause discolouration of teeth.
Amoxicillin, tetracycline and doxycycline antibiotics can also cause superficial staining of the teeth especially when given to children under the age of eight whose teeth are still developing.
Pregnant women who take tetracycline and doxycycline may give birth to a child with bright yellow teeth that eventually turn grey or brown over time.
Minocycline used for the treatment of acne, is another medication that can cause discolouration of the teeth.
Long term use of minocycline causes teeth to turn green/grey or blue/grey which rarely corrects itself even after stopping the medication.
Other medications cause intrinsic stains (stains that are permanent and interfere with the formation of the teeth).
Fluoride, known recognized to reduce the chances of dental decay in children and adults, can cause teeth to discolour when taking in excess, causing the enamel of the tooth to change.
The most common adverse effect of excessive fluoride is dental fluorosis.
In mild forms it appears as small, white flecks that are barely visible.
In acute cases it ranges between white opaque marks to dark stains and pitting.
Teeth can also discolour with advancing age.
Tooth discolouration in older people is generally caused by the enamel that covers the teeth getting thinner which allows the dentin to show through.
The dentin also naturally yellows over time adding to the discolouration.