Raleigh cosmetic dentist

If you don’t like the way your smile looks, or you feel self-conscious because your teeth are dingy or look yellow, you may be considering professional teeth whitening. This common technique can restore your bright, vibrant smile and keep it looking lovely for years to come with the proper care and dental hygiene. You may be wondering how it works, or if teeth whitening is safe for you to do. To clear up any confusion, our cosmetic dentist in Raleigh is taking a deeper look at the science of teeth whitening.

Call today to schedule your appointment with our cosmetic dentist


What Causes Teeth to Turn Yellow?

Teeth can stain and get a yellow or grayish look is caused by several factors. Extrinsic tooth stains are the stains on the surface of the tooth’s enamel due to an accumulation of dental pellicle film over your teeth that seeps into the porous surface enamel and are generally caused by: 

  • Food and drink, such as red wine, coffee, cola, or tea.
  • Smoking or chewing tobacco
  • Age (often a blend of extrinsic and intrinsic staining)

Intrinsic tooth stains occur when the dentin under the enamel and inside the tooth becomes discolored. Causes of intrinsic stains include: 

  • Antibiotic use, specifically tetracycline, as a child
  • Mother used tetracycline during second half of pregnancy
  • Excessive use of fluoride. 
  • Trauma to a tooth

Because tooth stains, both intrinsic and extrinsic are set in, they can’t be scrubbed away with a toothbrush and toothpaste. Instead, they have to be bleached away. 

What Is In Tooth Whitening Gel?

Most professional tooth whitening gels contain either carbamide peroxide or hydrogen peroxide as its active agent. Carbamide peroxide breaks down in the mouth into hydrogen peroxide and urea, so no matter what gel you’re using, hydrogen peroxide is the true whitening agent. However, carbamide peroxide may seem stronger than it actually is – for example, a 10 percent carbamide peroxide solution breaks down to only about 3.6 percent hydrogen peroxide. 

How Does Tooth Whitening Gel Remove Stains

While tooth whitening is often referred to as “tooth bleaching” this term is a bit misleading. While it does lighten teeth up to eight shades whiter with the right treatment, it’s not fading the stains and making them lighter. The gel seeps into the enamel and triggers an oxidation process that breaks up the stains.

Tooth stains, both extrinsic and intrinsic are made of compounds called chromogens. Chromogens can be either:

  1. Large organic compounds with conjugated double bonds making up their chemical structure, like beta carotene. 
  2. Compounds containing metals, often intrinsic

Hydrogen peroxide is able to react with the double bonds of the organic compounds, causing oxidation and removing the stains, making the teeth look significantly more white and bright. Metallic compounds in the chromogens may be significantly more difficult to whiten, often requiring sodium hypochlorite to trigger the oxidation. 

Professional Tooth Whitening to Remove Stains

Professional tooth whitening gels contain between 15 percent and 35 percent hydrogen peroxide. For in-office, single-visit whitening, a higher concentration is used to rapidly remove stains, though this causes more serious tooth sensitivity for patients. At-home professional whitening and multi-visit professional whitening contains much less, often between 10 and 20 percent hydrogen peroxide. 

Blue Light Usage

When looking at teeth whitening, you may see pictures of people holding a blue light to their teeth. This is a UV light that is often used during the whitening process. After the gel is applied to the teeth, a small UV light is pointed at the teeth, which can activate the peroxide and hasten the process. While it is completely harmless when used correctly, some people do find they get the same effects without it. 

Discuss Tooth Whitening with a Cosmetic Dentist in Raleigh

If you’re interested in teeth whitening, but you’re not sure if it’s right for you, the best option is to speak to a cosmetic dentist. They can sit down with you and determine if it’s the right option. In some cases of intrinsic staining or weak enamel, dental veneers may be the better option.


Call today to schedule a consultation with our cosmetic dentist!