Tooth whitening works, but the process may not make you smile

As discussed in our updated report on teeth whitening, there are several professional and over-the-counter options for getting brighter, whiter teeth. Although they all produce different results, tooth-whitening treatments share on thing in common: They can be unpleasant to use, especially at-home tooth-whitening products.

Tooth pain a common complaint

Perhaps the most common consumer complaint is of tooth sensitivity. This is due to the primary ingredient in tooth-whitening treatments: hydrogen peroxide or carbamide peroxide. The longer the peroxide (in whitening strips or gels) stays on the teeth, the more likely it is to cause discomfort as it seeps through the tooth enamel and dentin and into the sensitive pulp, according to the American Dental Association.

Experiencing tooth pain while using a tooth-whitening treatment isn't all that uncommon, either.  A 2006 article in Prevention magazine cites a University of Southern California study that says nearly half of all people using an over-the-counter tooth-whitening product experienced some degree of sensitivity. An MSNBC article from the same year chronicles a litany of reader complaints of pain -- some mild, some excruciating -- after using tooth-whitening products. 

Tips to avoid tooth pain

So what can you do to avoid tooth pain? WebMD.com offers several tips:

• Talk to your dentist before you decide to whiten your teeth. A simple cleaning may whiten your teeth sufficiently. Likewise, if you have fillings or other dental work, your dentist can tell you whether tooth whitening is a good idea or not.
• Choose an at-home tooth-whitening product with a moderate degree of peroxide (around 10 percent). If you experience pain, try a product with a weaker concentration.
• Don't leave tooth-whitening strips or gels on for longer than the recommended time.
• Don't drink coffee, tea, soda or juice for a few hours after using a tooth-whitening product.

Drooling another issue

We found another user complaint about at-home tooth-whitening products: They can make you drool. A lot. As Eleena De Lisser of The Wall Street Journal found out while testing Crest Whitestrips Classic (*Est. $20), tooth-whitening strips can cause you to drool. A lot. "You're supposed to be able to wear two strips simultaneously, but that opened the drool floodgates and the strips simply fell off," she writes.

Gels can be messy

Gels, which are applied to trays that you place in your mouth and bite down on, can also be messy. In a Good Housekeeping study, editors testing the Aquafresh White Trays (*Est. $40) found the trays ill-fitting and therefore messy or uncomfortable. Several users posting reviews at Amazon.com, Drugstore.com and TeethWhiteningReviews.com say they experienced pain and irritation. Some also mentioned that the whitening gel ran down their throats. When the tray is actually a comfortable fit for the user, however, reviews suggest that the product whitens effectively.

To whiten or not to whiten?

If you don't mind a bit of a mess -- and provided you don't have sensitive teeth or experience pain while using these products -- tooth-whitening strips and gels may be worth it. As with any dental issue, it's always a good idea to talk to your dentist before you try a tooth-whitening treatment.