Philadelphia magazine’s Top Dentists 2010: The White Stuff (for You)

All whitening products use oxygen molecules to lighten the shade of the tooth, says Joe Roberts, a partner at the Philly-based general dentistry office Philly Smiles, but they’re not all equally effective. “The best methods hold the oxygen against the tooth, so it bubbles into the enamel rather than out into the air,” Roberts explains. Which means all those “whitening” gums, rinses and toothpastes are best left on the shelf. And the rest? It’s a matter of your personality and how much cash you’re willing to shell out.

Whitening strips: Best for: Cash-conscious consumers, pre-date prep, do-it-yourselfers. Because: A box of these gel-lined strips (from $25 to $45) can be found in any drugstore. Pros: They hold oxygen against the tooth fairly well, so they’re the most effective OTC option (with results in as little as three days). Cons: They’re not custom-fit, so gel may touch gums, causing sensitivity. And you may need more than one box to reach desired whiteness.

Bleaching trays: Best for: Control freaks, sensitive teeth, coffee/soda addicts. Because: At-home application allows you to whiten as much or as little as you like. Those with sensitive teeth can alternate with fluoride gel to lessen pain. Pros: Once you pay for the initial trays (around $400), you can buy additional whitening gel (around $60) for touch-ups, or whenever teeth begin to lose shine. Cons: It looks like you’re wearing a mouthguard every night. And it will be two or three weeks of nightly treatments before you see a difference.

Lasers: Best for: Time-crunched makeovers, the routine-wary. Because: Lightens teeth six to eight shades in 90 minutes. Pros: The laser heat allows oxygen to penetrate deeper into enamel, so even tough gray strains caused by tetracycline exposure can fade. Cons: At $600-plus, it’s pricey, and you may need touch-ups in a year or so, depending on your coffee, soda and cigarette habits.