How Does Teeth Whitening Works?

How does teeth whitening works to remove tooth stains and make our teeth look whiter? Understand the process of teeth whitening. Includes a chart of results to expect.

What’s the magic behind teeth whitening? How can a tooth that is so discolored with brown and yellow stains and, in one hour be white as snow?

To have a better understanding on how teeth whitening actually works to make our teeth whiter, let's first learn a few basic facts on tooth anatomy and how tooth stains are formed.

• Our teeth are made up of a few different layers. The outer visible part of the tooth, the white part, is called the crown. The crown contains a layer of enamel that protects our teeth. Enamel is harder than bone.

• The layer underneath the enamel (and crown) is the dentin. This layer is composed of the same substance as bone, primarily calcium and phosphorus. Because dentine is composed of tiny tubules that connect to the nerve of the tooth, it can be sensitive.

• The pulp forms the very center of the tooth and contains the blood vessels, nerves and lymphatic vessels. Any pain sensations of heat or cold affect this part of the tooth. When you get a tooth infection, this area of the tooth comes to the rescue with white blood cells to clear it out.

How Our Teeth Become Stained and Discolored

Whenever we eat foods or consume beverages that contain pigments, these pigments have the opportunity to stain the teeth on the enamel layer.

When we brush our teeth immediately after eating a meal, we remove these stains from the surface of the tooth. However, if we don’t brush after eating, the pigments of those foods and beverages remain on the teeth enamel or in the cracks and crevices and begin penetrating the porous surface of our teeth.

The longer the pigment stays on the tooth, the deeper the stain thereby causing our teeth to look yellow and discolored. Eventually, these stains become more difficult to remove with conventional brushing and will require teeth whitening treatments to remove them and make our teeth bright white again.

How Teeth Whitening Works To Whiten Our Teeth

All teeth whitening treatments involve a bleaching agent that is applied to the enamel layer for a specified amount of time. The stronger the bleaching agent, the more it can penetrate the enamel layer and remove more stains. As the bleaching agent touches the tooth, it creates an oxidation reaction that penetrate the enamel and the dentin to attack and break down the stains.

The bleaching agents commonly used in teeth whitening include:

• Hydrogen Peroxide
• Carbamide Peroxide

The highest concentrations of bleaching agents are used in the in-office professional laser teeth whitening procedures. These are the same methods used on actors and actresses in the television show, Extreme Makeovers.

Teeth whitening offers a very effective solution against yellow or stained teeth caused by consumption of tobacco or tea, coffee, red wine or other foods and beverages. Many people see a noticeable difference after only one whitening session, while others may need repeated applications over a few days. Results depends on the strength of the whitening solution and which procedure is used.

On the other hand, a teeth whitening process may take longer if the tooth stains are dark brown or bluish grey. This kind of discoloration tends to sit deeper in the teeth, and is usually caused by consumption of antibiotics such as tetracycline while the teeth are still developing. If that is the case, the teeth whitening process will require several treatments over a period of one to three months.

In-Office Teeth Whitenng

When you go to your dentist or a specialist whitening center for an in-office professional teeth whitening (also known as a chair-side whitening treatment), the dentist will start by examining your teeth and taking X-rays of them.

She will then tell you about the different ways she can help you to obtain whiter teeth, how the treatments work and what to expect afterwards. Everyone’s teeth are different, and react in different ways to the stain removal process. As a trained professional, the dentist can judge how your teeth might take to a whitening session. However, you need to know that there are always risks with such a treatment, and that you might not get the desired effect every time.

The dentist cleans your teeth first with a pumice-like attachment, and removes any plaque along the gum line. Then she usually places a dental dam in your mouth to protect your gums, before applying the professional-strength bleaching gel to the teeth.

The whitening solution contains a high concentration of either hydrogen peroxide, or a more stable version called carbamide peroxide. At this point a laser may or may not be directed at the teeth to help activate the bleaching gel and release the oxygen molecules. Some gel formulations are self-activating and do not require a laser to give you whiter teeth.

You can also have a single tooth whitened. If you have had a root canal, the dentist can do a so-called walking bleach, where she opens the canal, fills it with whitening gel and seals it up again. The gel will need to be changed every week until the tooth reaches the desired color. For a tooth that has not had a root canal the whitening solution is applied on the outside in the usual manner.

One important point to remember is that most dental work such as crowns, bridges or white fillings cannot be lightened with bleaching gel. If you whiten your teeth you therefore need to have any visible dental work redone afterwards to avoid a mismatched look.

For the majority of patients, in-office teeth whitening offers a quick and easy way to get whiter teeth. Depending on the color and condition of their teeth before the treatment, some people find that they can go up to 10 shades lighter with only one hour-long session, while others need one or more follow-ups.

At Home Teeth Whitening Kits

Home teeth whitening kits work very similarly to the in-house dental procedures, using a peroxide gel, and comes with a generic tray that you can customize to attach to your teeth.

The advantages of using a home teeth whitening kit is it is a convenient and economical way to improve the appearance of your smile.

The disadvantages are usually the bleaching gel is usually less concentrated than the in-office version, and therefore you will need to use it several times over the course of one to three weeks to achieve maximum results.

How Teeth Whitening Methods Can Cause Sensitivity

One of the common side effects of many types of bleaching agents used in teeth whitening products or methods is tooth sensitivity. If the enamel of the tooth is worn down in areas exposing the more sensitive dentine layer, there will be tooth sensitivity when a bleaching agent is applied.

However, the good news is that the tooth sensitivity can rapidly disappear when the bleaching agent is removed. Often, a few days of discontinuation of the bleaching agent eliminates the tooth sensitivity.

Results of Teeth Whitening

The strength of the bleaching agent determines the results as well as how long the agent is applied to the teeth. Below is a chart of the types of whitening strength to be expected in different teeth whitening methods.

Now that you are familiar with teeth whitening and how it works, you can determine which method will work best for you. Get your brightest smile ever!