When the American Academy of Cosmetic Dentistry asked survey respondents what they'd most like to change about their smile, the number one answer was whiter teeth. Tooth whitening procedures run the gamut from dentist office light-and-laser whitening to at-home bleaching strips. Sometimes, however, the powerful bleaching agents can irritate gums, teeth and the network of nerves buried inside them.
The Whitening Process
Tooth whitening is accomplished through bleaching. If you have the procedure performed by a dentist, your teeth will be exposed to a bleaching agent often activated or enhanced by lasers or light, the American Dental Association notes. The dentist will protect your gums with a gel or rubber shield. If you whiten at home, self-whitening kits usually include a peroxide solution encased in a mouth guard that you wear for a specified period of time each day for one to two weeks. The effects last anywhere from several months to several years, depending on the strength of the bleach used and the original color of your teeth.
What Causes Sensitive Teeth?
Each tooth is made up of layers: enamel on the outside, dentin in the middle, and a pulpy nerve-filled interior. Dentin isn't hard and smooth like the exterior enamel, the American Dental Association explains--it's made up of tiny tubes that lead to the tooth's central nerves. When the enamel wears away, these tubes are left exposed. If you eat hot foods, cold foods, sugary foods or acidic foods, particles can slip through those tubes and irritate the sensitive nerves beneath. Similarly, when gum disease or overly aggressive brushing causes your gum line to recede, the dentin at the top of the tooth is exposed, causing the same sort of pain.
The Link between Sensitivity and Whitening
The American Dental Association warns that temporary tooth sensitivity is a known side effect of exposing your teeth to the bleaching solution. This sensitivity usually lessens over time, often a few days after the last bleaching treatment. If you had thin enamel before whitening, the bleach may accelerate enamel wear, causing sensitivity following your whitening treatment.
Permanent Sensitivity
Some people have permanent tooth sensitivity even before they whiten their teeth. If you routinely experience pain when eating ice cream or sticky candy, drinking hot or iced beverages or when sucking in air, consider seeing a dentist before whitening. There may be an underlying problem the dentist needs to solve, such as gum disease, a broken tooth, a cavity, or a tooth that needs a root canal.
Treating Sensitivity
Whether you have temporary or permanent sensitivity, the American Dental Association recommends using specially formulated toothpaste. Sensitive-formula toothpaste contains potassium nitrate, an active ingredient that blocks the nerve pain usually associated with sensitive teeth. Brushing with lukewarm instead of cold water and using a soft-bristled toothbrush can also help ease sensitivity. If these measures don't help, dentists can coat your teeth with fluoride gel that strengthens the enamel and reduces pain or seal the open areas between your tooth and gum.
