Teeth Whiteners
In 1938, DuPont began commercial production of nylon toothbrush bristles for the so-called "Miracle Tuft Toothbrush." Before 1938, the world relied on toothbrush bristles of neck hairs from wildwild boars and hogs. Today, chemists are still developing new materials to keep you smiling.
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As far back as the Middle Ages, people have been willing to go to great lengths for a bright-white smile. In those days, the neighborhood barber-surgeon–the guy you went to for anything from minor surgery to a haircut–would also file down your not-so-pearly whites and soak them in a concentrated solution of nitric acid. Patients did get the white teeth they were looking for. But the concentrated acid destroyed their tooth enamel, causing massive tooth decay later in life.
Today, people seeking dazzling white choppers, à la Julia Roberts, can turn to less extreme methods. A vast array of pastes, gels, and strips promises to give you a movie-star smile, and they work at home or in the dentist’s chair.
All toothpastes rely on abrasives to scrub stains from the tooth surface. The first “toothpowder,” created in England in the late-18th century, contained rather harsh abrasives, including brick dust and ground-up cuttlefish. Today, toothpastes contain milder polishing agents such as silica, aluminum oxide, calcium phosphates, or calcium carbonate. Some toothpaste manufacturers also offer products that rely on proteolytic enzymes and chelators to lift stains on the teeth.
To combat stains below the surface, you’ll probably need to turn to whitening gels containing hydrogen peroxide. The tooth-whitening power of peroxide was first recognized in the early 1970s. Dentists noticed that an oral antiseptic containing peroxide not only helped heal lesions in their patients’ mouths but also gave them whiter teeth. Today, peroxide-based gels for tooth whitening at home and at the dentist are a booming business.
Hydrogen peroxide works its magic by breaking down into water and oxygen via radical intermediates. It’s thought that these radical intermediates react with polyphenols and other pigments that stain teeth, at least in part by destroying the double-bond network that lends such compounds their color.
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Excerpted with permission, Chemical & Engineering News
Copyright © 2003 American Chemical Society