Wondering why you now have yellow teeth and not the normal beautiful white teeth? Discoloration of teeth is one of the most common problems that people experience. Teeth whitening becomes necessary with age.

The discoloration happens when the enamel layer starts wearing out. Many of our daily habits conspire to turn our teeth from white to yellow.

The food we eat, what we drink, and other habits e.g. smoking. However, the condition can be reversed. Teeth discoloration and staining happens mainly due to two sources of stain. Intrinsic and extrinsic staining.


This stain occurs due to environmental factors including smoking, pigments in beverages and foods, antibiotics, and metals like copper and iron.

Here are more reasons for intrinsic stains:

Dental plaque: A clear biofilm of bacteria that forms along the gum line. This occurs due to the normal development and defenses of the immune system.

Calculus: The hard deposit on the teeth especially along the gum line. This happens when the plaque has calcified. The color of calculous varies. It starts as yellow then overtime starts turning darker and becomes more tenacious and difficult to remove.

Tobacco: Tar in the smoke from tobacco products forms a yellow-brown-black stain around the necks of teeth above the gum line.
Betel chewing: The extracted gel of betel leaf contains tannin, a chromogenic agent that causes discoloration of the tooth enamel. Tannin is also present in coffee
Betel chewing produces blood-red saliva that stains the teeth red-brown to nearly black.

Others include certain topical medications, certain foods, and metallic compounds.

What to do to remove extrinsic stains


This is done using a slow-speed rotary hand piece and a rubber cup with abrasive paste, mostly containing fluoride.

Adversely, the action of the rubber cup together with the abrasive nature of the paste removes around one micron of enamel from the tooth surface every time prophylaxis is performed.

This method of stain removal may only take place in the dental office.


Pastes contain different abrasives. Hydrated silica, sodium bicarbonate, and calcium carbonate to polish and remove surface stains and /or low concentrations of active peroxide to bleach teeth.

The silica in most conventional whitening toothpaste mechanically scrapes stains off of teeth by using an abrasive called silica.

As far as toothpaste is concerned, always look for pastes that contain peroxide if you want real results. You start to notice the whitening after five or more days.

This stain removal method can only be undertaken in a dental office, not at home. Here, the dental professional treats by use of an instrument that emits a powder, water, and compressed air to remove biofilm, and extrinsic staining.

This stain removal method can only be undertaken in a dental office, not at home.


Unlike the extrinsic, here, the staining occurs during the teeth development. Either before birth or during childhood.

They are stains that cannot be removed through mechanical measures.

Here are some sources of intrinsic stains:

Tooth wear and aging

A progressive loss of enamel and dentine due to tooth erosion, abrasion, and attrition. As enamel wears down, dentine becomes more apparent, and chromogenic agents are penetrated in the tooth more easily.
The natural production of secondary dentine also gradually darkens teeth with age.


A rare metabolic disorder in which the body fails to adequately metabolize porphyrins, which leads to accumulation or excretion of porphyrins into teeth.
The excretion of porphyrins produces purple-red pigments in teeth.

Dental caries

Tooth discoloration is inconclusive, however, the most reliable evidence suggests that carious lesion allows for exogenous agents to enter dentine and hence increased absorption of chromogenic agents causing discoloration to the tooth.

Dental trauma

May stain either as a result of pulp necrosis or internal resorption. Alternatively, the tooth may become darker without pulp necrosis.


Dental fluorosis causes opaqueness of the enamel making them chalky white and porous, causing it to break down and cause the exposed subsurface enamel.
They occur due to excessive ingestion of fluoride or overexposure to fluoride during the development of enamel which usually occurs between the ages of one to four.

Restorative materials

The materials used during root canal treatments, such as eugenol and phenolic compounds, contain pigments that stains dentine.

Among many more.


In-Office bleaching of discolored teeth

This procedure generally uses a light-cured protective layer that is carefully painted on the gums and papilla (the tips of the gums between the teeth) to reduce the risk of chemical burns to the soft tissues.

The bleaching agent is either carbamide peroxide, which breaks down in the mouth to form hydrogen peroxide, or hydrogen peroxide itself.

Bleaching is least effective when the original tooth color is greyish and may require custom bleaching trays. Bleaching is most effective with yellow discolored teeth.
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