Your teeth have three layers; the pulp, which contains the nerves and blood supply, the dentin is tissue which surrounds it, and this is covered in the hard outer layer, the enamel. There are two types of teeth stains; extrinsic stains on the enamel and intrinsic stains in the dentin, which shows through the slightly translucent enamel.
Common causes of discolouration are red wine, coffee and cigarettes. Anything that stains white clothing can cause extrinsic stains. Also, the use tetracycline antibiotics and excess fluoride during childhood can cause teeth to become discoloured.
Also, a lack of proper teeth brushing habits can cause stains. Brushing your teeth too violently with a hard-bristled brush, or using abrasive toothpaste can cause the enamel to wear thin. Look for the American Dental Association (ADA) seal of acceptance on tubes of toothpaste.
But teeth naturally get darker as part of the ageing process, as the enamel surrounding your teeth becomes thinner.
Tooth whitening can be a very effective way of lightening the natural colour of your teeth without removing any enamel. Professional bleaching is the most common form of tooth whitening, your dentist will be able to tell you if you are suitable for the treatment.
The doctor will apply a shield to your gums before applying the whitening product onto your teeth. The product contains hydrogen peroxide which literally bleaches your teeth. The full treatment can normally be completed in a few visits to the dentist, and they may even issue you with a kit for you to apply to your teeth at home.
The effects can last up to three years, but this will vary from person to person. The whiteness will last less if you smoke or consume food or drink which stains. If you are a smoker or a heavy drinker of red wine, it may be worth considering either giving up, or accepting the fact that your teeth will never be white.
Home kits can be a cheaper way to whiten your teeth, although the effects are likely to be less prominent since the substance provided in these home kits contains a much lower percentage of hydrogen peroxide. You should still be careful applying this, though, as it can damage your gums if it makes contact.
There are lots of whitening toothpaste available, although they do not affect the natural colour of the teeth. They can remove any surface stains which can make a difference to the overall appearance.