A bright smile opening shiny pearl teeth is a sign of youth, energy and success. Unfortunately, with age, the smile gradually fades and comes back only after a visit to the dentist’s office, who performs clarification of teeth. But why, in fact, our smiles change their color and what actually happens in the doctor’s office during the procedure called whitening? We will give exhaustive answers to these questions.
Why do your teeth get darker?
Teeth change their color in only two cases – because of superficial or deep coloring of enamel.
When the enamel is superficially colored, it changes its color from the outside. As a rule, this happens because of:
- Consumption of products with coloring properties. Any products in which there are colorants – and it does not matter, synthetic they, as E-102 or natural, as wine, dark berries, soy sauce or tobacco – can change the color of tooth enamel. The coloring pigment of these products penetrates into microcracks of enamel, accumulates there – and in due course of time the person notices that his teeth have darkened.
- Poor oral hygiene. Inadequate brushing of plaque leads to the appearance of tartar on the enamel, which has a dull yellowish or brownish tint. By the way, professional tooth brushing can also brighten teeth by 1-3 tones.
With deep coloring, the enamel changes its color from the inside. In this case, it is not even the enamel that gets darker, but the hard tissues of the tooth underneath it. And this can happen for many reasons:
- As a result of taking medication. So, for example, taking such antibiotics as tetracycline and monocycline can stain the dentin of the tooth in yellow and gray.
- As a result of exposure to chemicals. For example, the increased content of iron in food and water (and thus in the body!) gives the dentin a red tint. Excess fluoride – partially coloring the tooth in milky white (so-called “chalk stains”).
- General diseases. Body health problems affect not only the diseased organ, but also the color of the teeth. For example, with severe forms of jaundice and hepatitis, teeth may change their natural shade to blue-green or brown.
- Age-related changes. Over time, the tooth enamel layer thinns and the dentin becomes darker. The combination of these factors leads to a change in the color of the teeth.
How does teeth whiten?
Tooth whitening is essentially the removal of pigment molecules from the tooth enamel structure. The most effective way to remove pigments is by chemical means – when darker pigment molecules oxidize and break down into lighter substances (oxygen, atomic hydrogen and water).
As an oxidizer of pigment molecules are hydrogen peroxide, urea peroxide, perhydrol or chlorine. During the whitening reaction, these substances, penetrating into the enamel, first “break” the compounds of pigment molecules into separate components, and then turn them into colorless molecules of hydroxyl group. Which, in turn, over time (1-2 weeks) are simply “washed” out of the tooth.
Not only effectively, but also safe for the tooth tissues are destroyed pigments in the enamel hydrogen peroxide and carbamide peroxide. That is why they act as an active substance in almost all whitening systems. However, different whitening systems contain different percentage of peroxide – for example, in home whitening systems, its concentration usually does not exceed 8-15%. And when whitening in the dentist’s office, compositions with up to 35% peroxide are used.
In addition to peroxide, the composition of the bleaching gel includes other substances that protect the tooth enamel. In particular, these are fluorides that reduce the sensitivity of teeth after bleaching and calcium, which fills the defects and scratches on the tooth enamel, making them smooth and shiny.