One of the two chemicals most commonly used in over the counter teeth whitening products today is hydrogen peroxide. This is the active ingredient responsible for the whitening results provided by many at home whitening gels, strips, and pens. This powerful chemical can provide great whitening results but care must be taken to use it safely and avoid potential side effects.

What is Hydrogen Peroxide?

Hydrogen peroxide is made up of two atoms of hydrogen and two of oxygen. It takes the form of a clear liquid resembling water but it functions as an oxidizer - a chemical that breaks down into oxygen. Because of this it is has many applications in cleaning and bleaching. For example, it is used to sterilize wounds and bleach hair. Teeth whitening is just one of the many uses of this chemical.

How Does Hydrogen Peroxide Whiten Teeth?

Hydrogen peroxide is a useful whitening agent because it breaks down into water and oxygen. It is the concentrated oxygen released by peroxide that actively breaks apart the chemical bonds holding together the stain pigments within your teeth. Unlike abrasive ingredients like baking soda that can only clear stains off the surface enamel of your teeth, the oxygen from peroxide can penetrate into the porous structure of your enamel and dentin to clean your teeth from the inside out. The yellow or brown discoloration on your teeth is the result of stain pigments from eating certain foods, drinks or from smoking. The oxygen tears apart these pigments at a molecular level, resulting in far whiter teeth than can be achieved with surface level cleaning.

How Does Hydrogen Peroxide Compare to Carbamide Peroxide?

Carbamide peroxide is also used for teeth whitening and in fact carbamide will break down into hydrogen peroxide. This means that a solution of carbamide peroxide has less concentrated whitening power than an equal percentage of hydrogen peroxide. It's only about a third as strong. A 30% percent concentration of carbamide peroxide is only as effective at bleaching your teeth to a whiter shade as a 10% solution of hydrogen peroxide. Despite this carbamide peroxide is popularly used in whitening products.

The reason carbamide peroxide is commonly used in at home whitening products instead of hydrogen peroxide is because it is safer to handle. Whitening products that include carbamide peroxide for whitening are safer to use and much less likely to cause side effects than hydrogen peroxide whitening gels which use stronger concentrations of peroxide. A good carbamide peroxide whitening gel can still get you the whitening results you're looking for, despite providing less peroxide.

Both carbamide peroxide and hydrogen peroxide are effective at whitening teeth. Don't worry too much about the relative strengths and concentrations of various peroxide-based whitening products. Instead of trying to find the highest concentration of hydrogen peroxide available in a whitening product you can get the whiter teeth you want with a lower and safer concentration of carbamide peroxide.

What Are the Potential Side Effects of Hydrogen Peroxide?

Unfortunately, because it is such a strong oxidizer hydrogen peroxide can cause side effects like temporarily increased tooth sensitivity or even chemical burns if allowed to come in contact with skin or the gums.

These side effects can be avoided however. To prevent tooth sensitivity that makes it painful to eat ice cream or drink hot soup you can use a restorative fluoride toothpaste featuring NovaMin to repair the structure of your teeth before whitening with a hydrogen peroxide gel. This will make your teeth less susceptible to that annoying side effect.

Preventing chemical burns is also easy. Just follow the manufacturer's directions exactly as written, carefully noting the amount of whitening gel to use. This will keep the peroxide gel from seeping out of its holding tray and coming into contact with your gums. Remember that using more gel will not whiten your teeth any faster. Don’t fill the tray with more gel than necessary.

You can also consider using a product featuring a lower concentration of peroxide to avoid side effects, but it will take more treatments to get the attractive white smile you're after.

What Teeth Whitening Results Will Hydrogen Peroxide Provide?

The results you'll get from treating your teeth with a hydrogen peroxide whitening product will vary depending on the severity of your dental stains, the concentration of the peroxide solution, how long each whitening session is and how many days you keep whitening. Because of all these different factors it's difficult to make a precise estimate of how effectively your teeth will be whitened, but peroxide products are the most powerful conventional whitening solutions available. Even dentists use peroxide when they whiten your teeth in a professional whitening treatment. You should expect a to have teeth that are at least a few shades whiter than what you started with, if you are using a quality ADA approved whitening gel.

How Long Will Whitening With Hydrogen Peroxide Take?

Just as with the whitening results it's difficult to estimate the length of time you'll need to whiten to reach your goal, but you can expect to see results within one to two weeks of daily treatment. This is far faster than whitening with toothpaste alone.

Do Dentists Use Hydrogen Peroxide to Whiten Teeth?

Peroxide is the most common way to whiten teeth other than abrasion. It's not just limited to over the counter products for home use. Dentists use it to whiten teeth in treatments within a dental office. These treatments can be expensive, costing several hundred dollars per session. Because of this it is far more cost-effective to try out whitening at home with peroxide gel and following up with whitening toothpaste to see if the results are good enough for you, before dealing with the expense of multiple professional whitening sessions.

If you choose to have your dentist bleach your teeth the procedure will usually take no more than an hour per session, with the number of sessions determined by how badly discolored your teeth are and how white you want them to be, as well as how many sessions you can afford.

The dentist will begin by cleaning your teeth with an abrasive, then cover your gums to prevent them coming in contact with the powerful concentration of peroxide that will be used, and finally apply the peroxide to your teeth.

What At-Home Teeth Whitening Products Contain Hydrogen Peroxide?

You can purchase diluted concentrations of hydrogen peroxide in liquid form as a general purpose oxidizer for use in cleaning or bleaching and use this form mixed with baking soda to whiten your teeth, but peroxide products made specifically for whitening teeth will produce the best results while also being safer to handle and use. Hydrogen peroxide is most commonly found as the active ingredient in whitening strips and you can also purchase whitening gels that use it, though the carbamide form of peroxide is more commonly found in whitening gels.

How Should Hydrogen Peroxide Whitening Gels Be Used?

Carefully follow the directions as written by the manufacturer and do not use more gel than specified to avoid side effects like gum irritation and pain. Specifics will vary from brand to brand, but generally you will use a tray to hold the gel in contact with your teeth for a short period of time per session, with one or two sessions per day as needed.