Drugstore aisles teem with toothpastes claiming to do everything from fighting plaque or curbing tartar to freshening breath or shielding sensitive teeth. But the most prominent claim, whitening teeth, can be misleading. The fine print reveals that most products promise to whiten by removing stains, not by lightening the base color of the teeth.

Moreover, our tests of 41 toothpastes found no correlation between those claims and stain-removing ability. Even the seven toothpastes that contain peroxide, the main bleaching ingredient in whitening strips and professional treatments, lightened or bleached out stains no better overall than other toothpastes.

We did find one toothpaste that stood out as a stain remover: Ultrabrite All in One Advanced Whitening (which doesn’t contain peroxide). At 28 cents per ounce, roughly one-tenth the cost of the priciest brand, it was one of the least expensive products we tested. Unlike its two closest competitors in stain removal, Ultrabrite was no more abrasive than average.

While none of the toothpastes was excessively abrasive, people with sensitive teeth or increased susceptibility to tooth or gum erosion might consider one of the gentler products. And certain toothpastes produced unusual sensations that some people may not like, such as a bitter taste or a burning feeling in the mouth.

Pick a product that cleans well. Look for one rated at least very good for stain removal--notably Ultrabrite, a CR Best Buy. Beyond that, most people who don’t have special needs can choose by personal preference and cost.

Consider a product claiming plaque or tartar control if needed. We didn’t test claims about preventing plaque or tartar (see Toothpaste terms), since that would require an extensive clinical trial. Products labeled “prevents plaque and gingivitis” or “tartar control” and bearing the American Dental Association’s seal must provide clinical-trial evidence that they perform those tasks better than standard toothpastes do. Other claims may or may not be valid.

For plaque removal, how you brush matters more than which toothpaste you use. But if you have excessive plaque (a major cause of decay and gum disease) or gingivitis (gum inflammation) consider Colgate Total, which bears the “prevents plaque and gingivitis” claim and the ADA seal. If you’re prone to tartar buildup, consider toothpastes with the ADA seal that claim to control the problem, especially Colgate Tartar Control.

Consider a gentle toothpaste in special cases. The products we tested ranged from low to the upper end of the moderate range in abrasiveness. Toothpastes within that range should cause no clinically meaningful pro­blems, the American Dental Association says. Indeed, the stiffness of your toothbrush and the vigor of your brushstrokes probably contribute to dental erosion more than differences in abrasiveness. But some of our dental consultants said that a less-abrasive paste might be preferable for people with tooth or gum erosion or sensitive teeth. If you have such problems, you might want to ask your dentist about choosing a toothpaste rated both good for cleaning and low-plus (L+) for abrasiveness. (None that rated L cleaned well.) Of those good-cleaning products, Aim Whitening was a particularly good buy.

Go for fluoride. The ADA advises everyone to use a fluoride toothpaste. Some evidence suggests that even adults with healthy teeth can benefit from them. Our tests found that all 40 products claiming to contain fluoride had amounts within the ADA’s acceptable range.

But the fluoride levels in two toothpastes, The Natural Dentist and Tom’s of Maine Natural Anticavity, were near the bottom of the range and substantially lower than the rest. We could not determine whether the other pastes would offer a clinically meaningful increase in protection against decay. But people particularly susceptible to cavities, such as those with dry mouth or significant gum recession, may want to steer clear of the two lower-fluoride products. And unless your dentist says that you’re getting too much fluoride, there’s no reason to use fluoride-free Tom’s of Maine Natural Antiplaque Tartar Control.

For sensitive teeth, seek a specially formulated toothpaste. The six we tested all contain potassium nitrate, an effective ingredient for shielding exposed, sensitive roots. One of the six, Crest Sensitivity, bears the ADA seal.

Note the strong-tasting products we flagged in the Ratings. While some adults might prefer a strong taste, a bitter, burning, or mouthwash-like sensation might discourage children from brushing.

Don’t worry about the sweeteners. Both Tom’s products we tested as well as The Natural Dentist Herbal Toothpaste contain no artificial sweeteners such as saccharin. But research has found no danger from ingesting the sweeteners in up to four diet sodas a day, let alone the tiny quantities you might swallow in toothpaste. “It would take about three months of brushing to get the amount you’d put in just one cup of coffee,” says Sebastian Ciancio, D.D.S., director of the Center for Dental Studies at the State University of New York at Buffalo.