The natural colour of the teeth is determined by the structure of the enamel and dentine and the content of organic and inorganic compounds in them. Typically, the enamel is a transparent layer. The dentine, which is located under the enamel, however, has a solid colour and it gives the actual colour of the teeth.
The natural colour of the teeth is genetically determined and varies in people from white to grey to light yellowish. Teeth discolouration occurs for different reasons.
People consume every day foods and beverages containing various colourings (natural or artificial), preservatives and raising agents. Regular use of coffee, cola, tea, red wine results in staining of the teeth. Smoking is another major factor leading to staining of the teeth, especially combined with the use of coffee. Staining of the teeth takes different period of time, depending on the strength and rigidity of the enamel. Yellowed teeth violate the aesthetic appearance of the smile and weaken the self-confidence of a person.
Fluorine accumulation in the enamel of teeth (due to high content of fluorine in the water, milk, or incorrect dosage during childhood) leads to fluorosis. It is characterized by unevenly distributed yellowish stains in the enamel of teeth.
Staining of the teeth can result from continued administration of various drugs in childhood (e.g. tetracycline antibiotics), which also leads to the appearance of yellow to brown stains on the teeth.
Discolouration of the teeth can occur in people involved in the production of paints, varnishes, gasoline, etc.
Necrosis of the pulp of the tooth (gangrene) results in darkening of the crown which becomes grayish. This is due to the decay of the tissue of the nerve. This darkening is a diagnostic sign that the tooth is dead.
After endodontic treatment (root canal filling), one of the filling pastes may penetrate into the tooth tissue and colour the tooth in pink or brownish hues depending on the composition of the paste.
Despite maintaining strict oral hygiene staining of the teeth remains and even professional cleaning and polishing does not give a satisfactory result, because colours have penetrated deep into the enamel.