Teeth whitening strips (Crest Whitestrips®)
Teeth whitening strips - What are they?
Whitening strips are a type of at-home teeth whitening product. They were first introduced in 2000 by Proctor & Gamble under the brand name Crest Whitestrips®. Since then, a multitude of companies have developed their own similar, equivalent products.
a) What's the advantage of using strips?
The main benefit of using teeth whitening strips is that they provide a way for a person to perform relatively effective bleaching treatments (on their own, at-home) without the use of gel-filled trays (which are often considered by users as inconvenient or too messy or noticeable to wear during the routine activities of their day).
b) What are whitening strips made out of?
The strips are clear, thin, flexible pieces of plastic (polyethylene) that have been coated on one side with a film containing hydrogen peroxide. The film acts as both the bleaching agent and the adhesive for the strip.
Advantages of "strip" design.
- As compared to all other (reasonably effective) at-home methods, this is probably the simplest, least-messy way to whiten your teeth.
- Since the manufacturer applies the whitener, the dose you use is very controlled and consistent. This helps to insure predictable whitening results and to minimize the risk for side effects.
- Because only one side of the strip is coated with the bleaching agent, it acts as both a barrier that helps to prevent the dilution of the whitener and minimize its contact with soft oral tissues. This helps to increase effectiveness and decrease the user's potential for side effects.
c) What type of whitener is used? / What's its concentration?
- Most strip products (including Crest Whitestrips®) are coated with a hydrogen peroxide-based whitener.
- Nowadays, the typical "entry-level" strip product is coated with a 10% hydrogen peroxide agent.
- Overall, the Whitestrips® brand offers products whose whitener ranges from around 6% up to 14% H2O2 (see table below).
Trends in whitener concentration and treatment times have changed.
In years past, "introductory" products featured strips coated with a 6% hydrogen peroxide whitener (for example Whitestrips® Classic). And their instructions typically called for performing 30 minute treatments twice per day.
Nowadays, entry level products tend to be coated with a whitener that has about a 10% H2O2 concentration (Crest Whitestrips® Vivid and Advanced Vivid). The difference being that these (potentially) more potent products are only used for 30 minute treatments once a day.
WhiteStrips® whitener concentrations.
Here's what we think is the hydrogen peroxide concentration of the whitener used with the various members of the WhiteStrips® product line.
This information has been collected from research and Crest® publications we've seen over the years. We can't be certain that it is (or still is) correct but presume that the numbers shown are accurate.
|Hydrogen Peroxide concentration of WhiteStrips®.|
|Whitestrips® Product||Hydrogen Peroxide (H2O2) Concentration|
|1 Hour Express||10%|
The effect of gel (whitener) load.
The concentration of a strip's whitener really makes up only half of the story. The total amount of gel placed on each strip will affect the overall per-treatment dosing of peroxide your teeth receive too.
This is important because teeth bleaching is a direct cause and effect equation.
- Greater peroxide exposure = Greater, more rapid whitening effect.
(To the extent of the tooth's ability to lighten.)
That means it's possible for a strip that has a lower concentration bleaching agent to deliver a greater dosing of peroxide, if it carries a thicker load of the whitener.
In the end, what all of this means is that it's essentially impossible for anyone who doesn't share in a company's proprietary product details (which includes pretty much all of us) to actually be able to calculate the potential effectiveness of different brands of strips, or even the individual items found in a single brand's product line.
d) How does the whitener work?
Whitening-strip science involves a process where the hydrogen-peroxide component of the whitener breaks down into molecules called "free radicals." These very reactive agents break up the large complex molecules found in a tooth's enamel that have caused its staining.
In general, the process of peroxide teeth whitening involves what's called thin-film chemistry. This simply means that tooth bleaching doesn't require a lot of peroxide but instead just enough to cover over the surface of the teeth being lightened.
Whitening-strip technique takes the concept of thin-film chemistry to an extreme. The coating of whitener applied to them is generally around 0.2 millimeters thick (the thickness of a piece of paper is usually around 0.1 millimeter). However, the exact amount that's placed varies from product to product.
How are whitening strips used?
In a nutshell, a strip is positioned over your teeth and then gently pressed into place. At the end of your session, the strip is simply pealed off and discarded.
(Instructions for using Crest Whitestrips® products.)
How long are the strips worn?
As mentioned above, historically strips (like Crest Whitestrips® Classic) were worn 30 minutes a day, twice a day. The trend now is for once-a-day use, typically for 30 minutes, using a strip that has a more concentrated bleaching agent.
Application times, as well as how many days strips should be worn, varies with different products and these manufacturer recommendations should be adhered to for best results and avoiding side effects.
(We outline application times for Crest Whitestrips® products on this page.)
Why do treatment times differ?
Dental research has shown that the whitening effect produced by peroxide tooth whiteners is simply a function of concentration and treatment time.
That explains why in the example above, using a (roughly) twice as strong strip for half as long, can generally be expected to create the same whitening effect.
[Using one Crest Whitestrips® Vivid (10% hydrogen peroxide) strip for one 30 minute treatment vs. using two Crest Whitestrips® Classic (6% hydrogen peroxide) strips for 30 minutes each.]
It's OK to quit early.
Of course, if a person has already achieved the whitening results they want before they've used the entire contents of their kit, or if the side effects they experience become unmanageable, treatments may be terminated at any time.
(Here's details about how to manage side effects by adjusting your treatment sessions.)
How effective are teeth whitening strips?
(Note: This section compares the effectiveness of using strips to other whitening methods. If you're looking for general information about when the process of teeth whitening will work (any method), use this page: Types of tooth staining and their treatment solutions.)
Most of the whitening strip studies we refer to below were performed using Crest Whitestrips® Classic (6% hydrogen peroxide, two applications a day, 30 minutes each, for 14 days).
This product has since been discontinued.
- A near equivalent, similar style strip is the Crest Whitestrips® Vivid (10% hydrogen peroxide, one application a day, 30 minutes, for 10 days).
- Another generally similar strip but with some design improvements is Crest Whitestrips® Advanced Vivid (10% hydrogen peroxide, one application a day, 30 minutes, for 14 days)
What does dental research say about strip effectiveness?
In general terms, you can expect that using one of the standard, introductory type of whitening strip products mentioned above will be about as effective (equal or almost equal) as using a tray-based system that utilizes a 10% carbamide-peroxide whitener.
This statement is based on the findings of several studies (Ferrari , Gerlach , Hannig , Karpinia ). However, some studies (Bizhang ) have found tray whitening to definitely be the more effective of the two. (page references)
In regard to comparisons with other methods, Gerlach  found strips to make a more effective choice than brush-on whiteners or whitening toothpaste. (There is nothing surprising or controversial about these findings. These systems are well know to be a distant third and fourth in effectiveness behind tray and strip systems.)
Teeth whitening strips typically make a good initial choice.
The above findings suggest that most people who use whitening strips should expect to see at least some level of results. And for a very large percentage of these people, this level may be quite satisfactory.
[Tray technique is generally accepted to be the unofficial standard for at-home teeth whitening systems, and the one to which all others are measured. And as compared to it, using whitening strips has some inherent disadvantages. But in light of it's ease of use, a trade off of possibly being less effective vs. more convenient is an easy compromise for many users to accept.]
If you need better results, discuss matters with your dentist.
There's no way to know precisely how effective any type of bleaching system will be for any one individual. There are simply too many variables involved including: Type of tooth staining, user compliance with directions, etc...
If after trying a whitening-strips approach you feel that you haven't achieved the success that you are seeking, discuss matters with your dentist. In light of your recent bleaching experience:
- They might suggest that a tray-based system should be used. This is the next logical, and frequently more effective, approach if you still want to use an at-home method.
- Or in-office whitening might be suggested if quicker results, or an inability to find time for treatments, are your overriding problems.
How long will the whitening effect of strips last? / Touch-up treatments.
It's common and normal that the lightening effect created by any and all types of whitening methods will fade over time.
What can you expect after using whitening strips?
Gerlach (2004) evaluated the use of two Whitestrips® products and found no significant color relapse after 6 months. These findings are on par with results reported for tray-based teeth whitening.
The degree or speed of relapse you notice can be influenced by chromogenic agents you consume. This includes coffee, tea, colas, red wine or tobacco products.
Touch-up treatments are easy with strips.
The individual packaging that's used with whitening strips makes them very convenient for periodic touch-up work such as once every month or two (or even longer intervals).
Just use the very few you need out of the box to refresh the look of your teeth. Then save the rest for the next time additional minor re-treatment is needed. For long-term storage, keep your extra strips in your refrigerator.
More frequent touch-ups.
As a solution for "daily staining" (something we personally think would be essentially impossible to detect), Crest® markets their Stain Shield® product.
This is a low-concentration peroxide strip whose application time is very short (just 5 minutes). The idea is simply that the daily use of these low-effect strips counteracts the normal fading process in real time.
Which to choose?
Between the two methods, daily vs. multi-month touch-up treatments, it would seem the latter would be by far the more cost-effective.
We can see how the use of daily touch-ups theoretically lends itself to a more consistent look over the long-term. We'd just be hard pressed to think that very many people would be in a position to notice, and disillusioned to think that it would be that significant of an issue to a person.
Full menu for this topic - ▼
- The basics about strips. - What are they?
- Instructions for wearing them.
- Things to know about this technique.
Other ways to whiten your teeth. -