Whitening and Bleaching
Sensitivity is a common issue with bleaching, with studies showing it occurs in 55-75% of people bleaching. Teeth are very porous, and bleach will penetrate through the enamel and dentin layers, reaching the tooth nerve in 5-15 minutes. We recommend that patients with sensitive teeth approach bleaching carefully and slowly. The adhesive strips can be good in this regard, as they are a relatively low cost way to test for sensitivity problems. Mild sensitivity can often be overcome by being patient and bleaching at a slower pace, not bleaching on consecutive days, applying the strip for a shorter time period (1/2 to 1 hr initially), or even cutting a strip to make a narrower version.
If you experience sensitivity, I usually recommend allowing time for it to completely subside before proceeding, slowly. If you have strong sensitivity, consider trying some desensitizing. OTC sensitivity products abound, but none of them available in the U.S. today offer a universally effective and noninvasive solution. Avoid sensitivity toothpastes, such as Sensodyne and others, as these are usually acidic, contain fluoride (which I do not recommend), sodium laurel sulfate, and other chemicals that are not good for your health. The most common active ingredient, potassium nitrate, is believed to act by having a numbing effect on the tooth nerve, which is counter to any concept of sustainability. At this time, the only professional product we recommend for generalized sensitivity is MI Paste, which is formulated to aid in remineralizing the tooth surface. If you know someone in Canada or the UK, have them get you OTC products containing Novamin, a very effective sensitivity ingredient that is actually made in the USA.
If your teeth remain very sensitive to bleaching/whitening no matter how mild the products you try, realize that you probably cannot lighten your teeth without significant risk to their health. And remember that whitening toothpastes, with their abrasives, will make sensitive teeth worse.