Teeth Whitening Basics

Teeth whitening is all about peroxide

Baby boomers have become a huge market for teeth-whiteners because teeth yellow naturally with age. The effect can be exacerbated by smoking, as well as by drinking coffee, tea and red wine. The most effective teeth-whitening agents use peroxide (hydrogen or carbamide) to bleach the deep layers of teeth where toothpaste can't reach. The whitening process usually requires daily application for up to two weeks, but light therapy and peroxide can be used in the dentist's office to speed things up and shorten the bleaching process to as little as one hour. Experts say bleaching works best for yellow stains and that gray teeth, which can result from certain antibiotics, are much harder to whiten.

Many of the reviewers represented in our All The Reviews Reviewed chart test one sample from each of the different types of teeth whitening kits and services and then determine which method produces the greatest effect with the least inconvenience. We also look to research abstracts presented at the annual General Session of the International Association for Dental Research, where dental scientists test specific whitening products (primarily Crest strips) against each other. The manufacturers sponsored some of these studies. We find it interesting that the study results almost always favor the manufacturer funding the study. However, the findings do show that the effectiveness of tooth whitening products depends largely upon the percentage of peroxide in the product combined with the length of time the product is in contact with teeth, which is the same conclusion drawn by other experts and reviewers.

Store shelves are filled with so-called teeth-whitening toothpastes (*est. $3 to $7), which usually cost more than regular toothpaste. However, most reviews say that whitening toothpastes are less than impressive and that you can achieve the same result by brushing for the recommended two minutes with regular toothpaste. This is because peroxide and time are both needed to have a whitening effect on teeth. Many whitening toothpastes only contain abrasives or chemical polishing agents that clean the surface of teeth just like ordinary toothpaste; those that do contain peroxide aren't in contact with your teeth long enough to have much of an effect. Most reviews say you are better off brushing well with ordinary toothpaste and putting those extra dollars toward a true bleaching product.

Our report on toothpaste covers products that best clean surface stains, which reviews say is about all you can expect from toothpaste. We find that whether or not a toothpaste says "whitening" on the tube makes no difference in its performance.