Before we whiten our teeth we have to examine why there is a need to whiten them in the first place. The fact is that our teeth become stained over time. Depending upon what you eat, consume, drink or smoke this staining may be more pronounced than it is with other people.
The outer layer of teeth is called enamel. This layer’s role is to protect your teeth. It is also the layer upon which a new layer is built. All the things we consume or that pass by way of our teeth causes a new layer to accumulate and this forms a film that attaches to the enamel.
Dentists can of course remove this film, and brushing our teeth also has some effect at removing it. Abrasive toothpastes are particularly effective at breaking down this accumulation layer. By the time we introduce whitening toothpastes the scrubbing off of this layer becomes even more pronounced.
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So, why aren’t our teeth white yet? The problem is that the staining layer builds up over years and during that time it seeps into the enamel itself. Enamel is porous which allows much of the staining materials to become part of the tooth itself. In this case, scrubbing won’t remove these unattractive additions. Where this isn’t harmful to the tooth, it doesn’t win any contests either.
Tooth whiteners are able to remove these stains by using bleaching chemicals that work in the enamel layer. This process is referred to as “oxidation,” and it breaks up the staining compounds deep in the enamel.
Whiteners actually use the same chemical used to bleach hair: hydrogen peroxide. It is delivered in the form of “Carbamide Peroxide” but turns to hydrogen peroxide and then the true stain cleaning begins.
