11 things you need to know about tooth whitening

Tooth whitening FAQ’s

• 1. Do I need tooth whitening?

Tooth whitening is used because teeth can stain easily with the foods and drinks you consume, the worst offenders being: tea, coffee, red wine, tomato sauce, curry, balsamic vinegar, soy sauce. Think of it like this: if it stains your clothes it will stain your teeth.

Teeth also become discolored with age as well. Teeth have a natural yellow color due to the structure of the tooth: the outer enamel layer has a bluish white color and is highly translucent, so the yellow color of the inner dentin layer shows through to make the overall color light grey or light yellow.

If you feel your teeth are not as white as they used to be or they are not as white as you would like them to be you might want to consider this type of treatment.

• 2. Types of professional tooth whitening

*Home custom tray whitening:

For this you need to have whitening trays made, which are like customized retainers for your teeth. This customized trays have compartments built in them to accommodate the beaching gel. Very effective whitening method, it whitens teeth gradually.

*In office whitening:

Very popular tooth whitening option, as the effects can be instantly noticeable. In order to reach that result a much higher concentration of whitening gel is used, which is only available to dental professionals. In office whitening is light activated, which speeds up the penetration of the whitening gel in the tooth.

• 3. How it works

The whitening gel’s active ingredient is hydrogen Peroxide. Hydrogen peroxide breaks down into water and oxygen gas. The oxygen penetrates the enamel and dentin, bleaching colored substances while the structure of the teeth is unchanged.

Tooth whitening gels can be either hydrogen peroxide or carbamide peroxide. They are basically the same, because carbamide peroxide contains hydrogen peroxide at a ratio of 1:3.  For example, a product with 16% carbamide peroxide has about 5.7% hydrogen peroxide.

Both active substances hydrogen peroxide and carbamide peroxide both produce the same results. The difference is that hydrogen peroxide breaks down faster than carbamide peroxide, so it releases most of its whitening power within 30-60 minutes. Carbamide peroxide, on the other hand, releases about 50% of its whitening power in the first two hours and can remain active for up to 6 additional hours. 

This means that products using hydrogen peroxide have shorter wear times. However, the number of days a person will need to use either one depends on the individual’s unique needs and rate of tooth color change.

• 4. How white can they be?

There’s a limit to how white one’s teeth can be, this depends on every person’s individual tooth structure and staining level and the type of staining. A point will be reached where no more whitening will happen. This may or may not be the desired result.

• 5. How long does it take?

This of course depends on many factors, for example the concentration of the bleaching gel and the type of staining you’re trying to whiten.

In case of average staining due to long term exposure to coffee, red wine, etc. whitening will take around 6 weeks and requires wearing the whitening trays 5-6 times weekly.

Depending on the bleaching gel concentration you will have to adjust the duration of a bleaching session:

Concentration	Wear time
10% hydrogen peroxide	30-60 minutes
10%carbamide peroxide	8-10 hours/overnight
16%carbamide peroxide	4-6 hours

The first 2 weeks are the most important as in this time frame about 90% of total whitening effect is achieved. Usually after 6 weeks the whitening limit is reached, after this it’s unlikely the teeth will get any whiter.

Some discolorations can be very stubborn, which requires more time or stronger bleach concentration.

Regardless of whitening methods color relapse will occur over time.

For most people once they reach the desired shade studies have found the result lasts from 1 to 3 years.

After the desired shade is reached, a maintenance whitening can be performed once every 1-2 months, which will keep the results lasting longer.

• 6. Will my teeth become sensitive?

Some people experience transient mild to moderate tooth sensitivity, which usually disappears within 1-3 days of completing the whitening treatment.

The sensitivity can manifest as thermal sensitivity(to hot and cold foods and drinks, cold air) or generalized tooth discomfort.

There is no noticeable difference in sensitivity, regardless of whether you are using a hydrogen peroxide or carbamide peroxide product.

• 7. How much does it cost?

Tooth whitening can be quite costly if done at the dentist office, it can range between 200-500 Euros depending on the type of whitening(in office or at home tray whitening).

• 8. Will my crowns/veneers get whiter?

No, your crowns/veneers/fillings will not change color. So if you have dental work planned on some of your teeth, you need to do the whitening first.

Once you have finished the whitening treatment usually it’s recommended waiting 2 weeks before continuing dental work as there is typically a relapse of the tooth shade before it stabilizes.

• 9. Diet considerations during/after treatment

There are numerous factors that can cause teeth to discolor. And even though your teeth have been lightened, these same processes will continue to occur.

For example, people who have continued exposure to coffee, colas and tobacco products can expect that the luster of their original treatments will fade faster than those who don’t.

• 10. Is it safe?

The free radicals released by the breakdown of hydrogen and carbamide peroxides interact with the soft tissues it comes in contact with and can cause soft tissue irritation, but this is temporary, studies have shown no long-term ill effects.

In the 25 year history of the use of tray whitening has not demonstrated any cause of concern regarding the tooth enamel if used appropriately and according to the instructions. Of course overuse should be avoided.

Hydrogen and carbamide peroxide penetrates the enamel and dentin in 5-15 minues and reaches the nerve, however reasearch has shown the quantity is too low to cause permanent nerve damage.

• 11. Can pregnant women, children and adolescents use it?

The American Dental Association Does not recommend performing whitening during pregnancy and breastfeeding due to the lack of research.

Whitening is contraindicated for children under 18 years of age.