Do whitening toothpastes really work?

Yes, they do, but be careful how you pick them. Unlike teeth-bleaching trays or strips, whitening toothpastes scour away surface stains with the help of gritty substances like silica hydrate, which can eventually wear away tooth enamel. And if you have sensitive teeth, more grit can mean more pain. A paste with an RDA between 100 and 150 is considered highly abrasive; don't even think about going over 150.

Bottom line: Sand-papering your teeth isn't the best way to get them white. Stick to a gentler toothpaste-and try trays, strips, or a trip to the dentist to up the wattage of your smile.