Tooth whitening is the use of bleaching agents to lighten the colour of the teeth. The normal colour of tooth enamel (the hard-outer surface of each tooth) varies, with most teeth ranging from off-white to light yellow. Teeth may be discoloured by various factors.
What causes our teeth to stain:
Extrinsic (external) Stains - Extrinsic stains occur when the outer layer of the tooth, also known as the enamel, is stained. This may happen because of several factors:
- Diet - Frequently consuming coloured foods like coffee, tea, red wine, or any dark coloured foods or drinks can stain your teeth over time.
- Smoking - Nicotine and tar in tobacco stains your teeth severely, giving them a yellowish-brown colour.
- Poor dental hygiene - Accumulated dental plaque and calculus formed on the teeth due to poor dental hygiene can cause discolouration of teeth, which varies between grey, yellow, black or brown.
Intrinsic (internal) Stains - Intrinsic staining takes place at the deeper layer of the enamel and the dentin, which is the tissue lying below the enamel. These stains can range from bright white spots to a yellowish or greyish hue.
- Environmental factors - Excessive usage of fluoride products such as mouthwash, toothpaste, or drinking water with high fluoride content when younger, can cause your teeth to be discoloured.
- Antibiotics - Giving certain antibiotics to children whose teeth are still developing can stain their teeth, which will carry into their adult life.
- Dental trauma - Teeth can be discoloured from the inside out due to bleeding within the tooth itself, which decomposes and forms a blueish-brown stain.
- Genetic factors - A small number of people who suffer from congenital issues may also have discoloured teeth.
- Age-related Factors - The outer layer of the enamel on our teeth gets eroded when we turn older, exposing the dentin. As the dentin also turns yellow with age, this will cause our teeth to appear stained.