Dental bleaching, also known as tooth whitening, is a common procedure in general dentistry but most especially in the field of cosmetic dentistry. A child's deciduous teeth are generally whiter than the adult teeth that follow. As a person ages the adult teeth often become darker due to changes in the mineral structure of the tooth, as the enamel becomes less porous. Teeth can also become stained by bacterial pigments, food-goods and tobacco. Certain antibiotic medications (like tetracycline) can also cause teeth stains or a reduction in the brilliance of the enamel. Tooth bleaching is not a modern practice. Ancient Romans, for example, utilized urine as a product to make and keep their teeth whiter.
According to the FDA, whitening restores natural tooth color and bleaching whitens beyond the natural color. There are many methods to whiten teeth, such as brushing, bleaching strips, bleaching pen, bleaching gel, laser bleaching, and natural bleaching. Traditionally, at-home whiteners use overnight trays containing a carbamide peroxide gel which reacts with water to form hydrogen peroxide. Carbamide peroxide has about a third of the strength of hydrogen peroxide. This means that a 15 percent solution of carbamide peroxide is the rough equivalent of a five percent solution of hydrogen peroxide. Over the counter kits whiten with small strips that go over the front teeth. The peroxide oxidizing agent penetrates the porosities in the rod-like crystal structure of enamel and bleaches stain deposits in the dentin. Power bleaching uses light energy to accelerate the process of bleaching in a dental office. The effects of bleaching can last for several months, but may vary depending on the lifestyle of the patient. Factors that decrease whitening include smoking and the ingestion of dark colored liquids like coffee, tea and red wine. Dentures can also be whitened using denture cleaners.
UV light-enhanced tooth bleaching is not only a con, but is dangerous to your eyes and skin, says a Royal Society of Chemistry journal.
The light treatment gives absolutely no benefit over bleaching without UV, and damages skin and eyes up to four times as much as sunbathing, reports a study in Photochemical & Photobiological Sciences.
Those looking to match Tom Cruise's glittering pearly-whites would be better off ignoring claims of better bleaching with UV light treatment.
The treatment is at least as damaging to skin and eyes as sunbathing in Hyde Park for a midsummer's afternoon - one lamp actually gave four times that level of radiation exposure.
And as with sunbathing, fair-skinned or light-sensitive people are at even greater risk, said lead author Ellen Bruzell of the Nordic Institute of Dental Materials.
Tooth bleaching is one of the most popular cosmetic dental treatments available. It uses a bleaching agent - usually hydrogen peroxide -to remove stains such as those from red wine, tea and coffee, and smoking.