Whitening teeth using "whitening strips" can provide an alternative system to tray-based teeth bleaching. Proctor & Gamble introduced this whitening technique in 2001 with their Crest Whitestrips ® product. These strips come in two over-the-counter versions:
The strip portion of the Crest Whitestrips ® product is made out of polyetheylene. This type of plastic allows the strip to be very thin and quite flexible. One side of the Crest Whitestrip ® is coated with hydrogen peroxide bleaching agent. The composition of this whitener is adhesive in nature and provides a means by which the strip adheres to the surface of the teeth being whitened. Since the whitener is only placed on one side of the Crest Whitestrip ®, contact between the bleaching agent and the tooth surface is maximized while exposure of the whitener to soft oral tissues and saliva is minimized somewhat.
( It's always best to have a dental exam performed by your dentist before you use any teeth whitening product. [ More about the prudence of having a pre-whitening treatment dental examination. >> ] )
Each Crest Whitestrips ® kit contains strips specifically shaped for use on either upper or lower teeth. The whitening strips are placed on and folded over a person's teeth so the strip-to-tooth contact is as intimate as possible.
Most people will find that each strip is long enough to cover over at least their center six front teeth ("eyetooth to eyetooth"). Whitening strips are used on a one-time basis and then discarded. For the most part the whitening strips are transparent and except under fairly close inspection others might not know that you are wearing them.
The recommended regimen for Crest Whitestrips ® (the original version) is to wear them for 30 minutes, twice a day, for two weeks. The instructions for Crest Whitestrips ® Premium state that you should wear the strips for 30 minutes, twice a day, for 7 days. The difference in the treatment duration for each respective product is based on the fact that they each contain different concentrations of peroxide whitener.
The bleaching agent utilized in Crest Whitestrips ® is hydrogen peroxide. Crest Whitestrips ® (the original product) has a 6% hydrogen peroxide whitener applied to it. The concentration of the hydrogen peroxide applied to Crest Whitestrips ® Premium is 10%. In comparison, tray-based teeth whitening using a 10% carbamide peroxide whitener delivers an equivalent hydrogen peroxide concentration of about 3.5%.
Crest Whitestrips ® are unique in the fact that since each strip comes with the bleaching agent already applied, the dosing of peroxide the user receives during each application is very standardized. This is in contrast to other at-home bleaching systems where the precise amount of whitener used is dependent on the activities of the individual user.
This standardized dosing is a "good thing". It makes inadvertent inappropriate use by the end user more difficult. It also makes an evaluation of the safety of the product and its technique easier.
Proctor & Gamble seems to have created their Crest Whitestrips ® product to be an alternative to tray-based at-home teeth whitening technique. There are several clinical studies published in the dental literature that suggests that this bleaching technique can provide results somewhat on par with tray-based bleaching using 10% carbamide peroxide.