The most wide-spread negative consequences after
teeth whitening include:
*chemical burns - it occurs when there is a high-concentration of oxidising agent and it contacts tissues that are badly protected, which may bleach/discolor mucous membranes;
*sensitive teeth - heightened sensibility often disappears after treatment is over;
*overbleaching - the profession term is "over white teeth".
One of the other
cons that tooth whitening has is a hypothesis about its contribution to appearance of oral cancer. Hydrogen peroxide that is a part of whitening gels has been shown to promote an increase of cancerous tumors inside the cheeks of rodents and cause gastrointestinal cancers when swallowed. There were no experiments on humans, but the researches in this field advise to think twice before tooth whitening.
This procedure may also not meet all expectations of a person. The main reason is that whitening does not change color of artificial components in/on teeth (fillings, some other restoration materials). Not all
tooth whitening methods are appropriate for one person, they should be carefully studied and chosen to avoid unpleasant and undesirable effects. There is also one tip that yellow teeth yield to whitening well, but other tints (dark, gray, blue etc) may not be whitened at all.
People who have allergy to even to one of the components of
whitening products are not recommended to undergo bleaching. The doctors do not advise tooth whitening to children under sixteen years old because their tooth nerves increase with organism maturing. Women who are expecting to have a baby and are breast-feeding should not agree to bleach their teeth during these months either.
