Posted: Mar 29, 2011 3:16 PM
Everyone loves a dazzling smile. That's why so many of us reach for the bleach when our pearly whites start to look more like kernels of corn.
Common foods and drinks, such as coffee, red wine, and berries, and, of course, smoking, cause teeth to stain and lose their brightness. The effects are often exaggerated as we age, says Mark Wolff, DDS, PhD, professor at NYU College of Dentistry. Wear and tear creates etchings on the tooth surface, "making teeth more susceptible to stains," Wolff says. That's why you might notice that foods you've been eating for years discolor your teeth more these days.
Teeth whiteners, sold by dentists and drugstores, use a form of peroxide (hydrogen and carbamide are the most common) of varying strengths to oxidize or eat away at the tooth's color particles to brighten smiles. The amount of peroxide in store-bought kits ranges from 3% to 10%; in professional-grade whiteners (available in your dentist's office), it runs as high as 35%.
It is true that professional whiteners are generally more effective than those sold over the counter, but not just because the concentration of peroxide used is higher. More important for effective whitening, Wolff says, is that whitening trays made by dentists are molded especially for your mouth, keeping bleaching solutions in close contact with the tooth's surface. This not only enhances the whitening effect but also increases safety by minimizing the amount of peroxide that contacts the gums or is swallowed. However, that personalized fit will cost you: Professional whitening systems range from $400 to $800, compared with $25 to $100 for products you buy in the store.
But lower cost doesn't necessarily mean poor quality, and OTC whiteners can be a good option, Wolff says. Whitening strips are your best bet because they adhere reasonably well to the tooth surface, particularly on the top teeth, keeping gel where it can best penetrate enamel.
White teeth are alluring, but keep expectations in check. "There's only a finite color change you can achieve," Wolff says. Two or three shades lighter than your current color is reasonable. And be sure to follow instructions. Overdoing whitening efforts can harm tooth structure, leading to translucence -- see-through teeth that appear blue or gray.
That's why transforming a dull, yellow smile into a bright, white one is best handled like most things in life: "Everything in moderation," Wolff says.
Wolff offers some tips for safely whitening your smile:
Beware of tooth sensitivity. Tooth and gum sensitivity is a common side effect of teeth whiteners. "You don't want to use the strongest and fastest [solution] because it comes with the most side effects," Wolff says.
Watching bonding and veneers. If you have bonding or veneers on your teeth, whiten before having dental work done or skip it altogether. "These don't whiten with bleaching agents," Wolff says. Restorations will maintain their original color while the teeth around them lighten. The end result is a multicolored smile.
Choose whitening strips. OTC whitening strips are a better bet than store-bought trays. "The trays tend to be loose and so don't provide a high enough concentration [of solution] to really do the job of bleaching," Wolff says.
Skip whiteners if you have gum disease. Instead, talk with your dentist about alternate ways to brighten your smile. Whiteners can accelerate gum disease.