Discoloration of teeth

Colour of teeth

Since the enamel of permanent teeth is slightly transparent, the yellowish colour of the underlying dentine is shown through it. Therefore, permanent teeth will appear slightly yellowish. As we get older, the dentine increasingly grows thicker, and it is normal that our teeth become more yellowish.
Photograph of a set of yellowish permanent teeth.
Slightly yellowish permanent teeth

The enamel of deciduous teeth is not as transparent as our permanent teeth. That is why deciduous teeth look milky white
Photograph of a set of milky white deciduous teeth.
Milky white deciduous teeth

Factors causing tooth discoloration

There are two factors causing tooth discoloration — internal factor and external factor.

External factors causing tooth discoloration

Brown and black stains on the surface of teeth

Photograph of black stains on the inner surfaces of lower front teeth.
Teeth with black stains

Cause
Drinking of dark-coloured beverages, such as tea, result in the food colours being adsorbed onto the tooth surfaces.

Treatment
The dentist will use:

Prophyjet cleaning
 Photograph of lower teeth after removal of black stains.
Teeth after stain removal

Prevention
Avoid drinking dark-coloured beverages to minimize food colours being adsorbed.

Green and orange stains at the surface of teeth

Photograph of front teeth with orange stains.
Teeth with orange stain

Cause
Teeth has not been cleaned thoroughly, and the accumulated dental plaque contained bacteria or fungi that can produce colour and formed green and orange stains.

Treatment
Dentist will perform scaling to remove accumulated dental plaque and stains.
 Photograph of front teeth after removal of orange stains.
Teeth after orange stain removal

Prevention
Brush the teeth every morning and before bed at night, and use dental floss to remove dental plaque to keep the teeth white.

Internal factors causing tooth discoloration

Photograph of front teeth after removal of orange stains.

Teeth appear to be greyish-blue to brownish-yellow

Cause
If there was certain sickness or, if tetracycline (a kind of antibiotics) is taken during the development of teeth, the teeth formed will be greyish-blue to brownish-yellow.

Treatment

Teeth appear to be greyish-black

Cause 2
Tooth decay
Photograph of a set of deciduous front teeth some of them show black tooth decay.

Treatment
The dentist removes the tooth decay, and then puts on a filling.
Photograph of a set of deciduous front teeth having the black tooth decay removed and then restored by a tooth-coloured filling.

Cause 2

Pulp necrosis
Photograph of an upper incisor turning greyish-black.

The pulp becomes necrotic because of tooth trauma or tooth decay, and the tooth will appear greyish-black.

Treatment
Endodontic treatment must be done to treat the discoloured tooth which has pulp necrosis.
Photograph of that greyish-black upper incisor turning ivory white after root canal therapy.

Tooth after root canal therapy

If teeth still appear greyish-black, dentist can treat the discoloured teeth by bleaching, laminate veneer or crown.

Brownish-yellow or white patches at the surface of a tooth

Photograph of a set of permanent teeth with brownish-yellow patches.

Cause

If a deciduous tooth is so decayed that the pulp is exposed, the bacteria, via the apex of the tooth, will cause an infection in the vicinity of the developing permanent successor. This will disturb the development of the enamel of the permanent tooth, resulting in the formation of brownish-yellow patches

Long term excessive fluoride ingestion will alter the development of the enamel of teeth. This disturbance will show as white patches on the teeth.

Treatment

Dentist can apply topical fluoride onto the surfaces of teeth so that the early tooth decay lesion can be remineralised.
Photograph of one of the lower back teeth having its chewing surface applied with topical fluoride.

Treatments such as Filling, Laminate veneer or Crown
Photograph of a set of front teeth after filling with composite resin.

Tooth after filling

Last revision date: 18 January 2012