Teeth whitening involves the application of a ‘bleaching’ agent to the tooth surfaces to make them whiter and brighter. The material used is an oxygen liberating agent such a Hydrogen Peroxide or Carbamide Peroxide. This is not to be confused with tooth ‘cleaning’ which may whiten teeth by removing the (tobacco, coffee, red wine induced) surface staining only.
The bleaching effect doesn’t last for ever; perhaps two or three years.
There are two ways of applying the material: ‘in surgery teeth whitening’ and ‘at home’; often both are used … with the patient following up ‘at home’ application after the ‘in surgery’ procedure is completed.
The former involves a two hour session in the dental chair (with a relatively higher concentration of material) and the application of a special light. The latter requires a thin plastic mouth guard to be made, which carries a lower concentration of material to be kept on the tooth surfaces for about one hour a day for a week or so.
Not long ago, we received a European Union directive limiting the concentration we can use, so nowadays we need to go to more effort to get the same result as was achievable a few years ago.
Some ‘organisations’ do offer teeth whitening at very low fees. One has to be careful of exactly what the chemical used is! There are no miracles. Legally now, only dental practices are allowed to administer this treatment.