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Teeth
Whitening |
Tooth Whiteners For Tooth WhiteningTooth Whiteners For Tooth Whitening: Before we get into the details of tooth-whitening, let's take a minute
to meet the enemy. What are tooth stains anyway?
 Each of your teeth is made up of an inner dentin layer and a hard outer enamel layer, which protects the teeth. When you put stuff in your mouth -- food, cigarette smoke, coffee, etc. -- another layer gradually forms on top of the enamel layer. Basically, the foreign material accumulates to form a pellicle film over the enamel layer. A dentist can clean away this film, through scraping and chemical treatments. Even brushing your teeth can knock out some of it -- brushing with the abrasive toothpaste cleans the tooth in the same sort of way scrubbing with an abrasive pad cleans a dish. "Whitening toothpastes" are designed to work even harder on this layer. The problem is, as this pellicle layer sits on your teeth for years and years, the foreign material gets into the enamel. The enamel layer is made up of hydroxyapatite crystals, which form microscopic hexagonal "rods." Simply put, enamel is porous, which means staining agents can work their way down into the tooth, where you can't simply scour them away. The deeper stains are basically harmless, but many people find them unattractive.
Most tooth whiteners use one of two chemical agents: carbamide peroxide or hydrogen peroxide (the same stuff that will bleach your hair). When used in the mouth, carbamide peroxide breaks down into hydrogen peroxide and urea, with hydrogen peroxide being the active whitening ingredient. There are a number of different ways of setting off this basic process. |
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