Putting electric and traditional toothbrushes to the test. 

Which toothbrush to buy? I asked a scientist from the American Dental Association and a practicing dentist, and both advised me to buy any brush—as long as it's soft-bristled. A soft brush works great on plaque (which has the consistency of mayonnaise), while the firmer bristles gain you nothing. In fact, they say, you risk "toothbrush abrasion" if you combine hard scrubbing with firmer bristles: You slowly scrub a groove into your gumline and corrode your tooth's insides. Bad news, that.

Beyond this, there's little clinical difference between any two brushes, electric or non. Choosing comes down to comfort, motivation ("the gimmick factor") and, above all, maneuverability. For these you'll have to trust my teeth as testing grounds. On to the research.

Manual

I tried more than 30 manual brushes. The following stood out, for good or for bad. (Whenever possible, tests were performed using Colgate Total toothpaste, winner of the previous "Paste Test.")

Mentadent Surround: The Surround, with its standard head, is completely unexceptional save for its magnificent handle—a two-tone art deco masterpiece of molded plastic. Buy this one as your "show brush" to put in the guest bathroom and never use.

In seriousness, a good grip can be important if it helps you manipulate the brush. The goal in brushing is to cover every tooth surface, so if fancy grips or angled heads do the trick for you, stick with 'em. The Surround grip, while pretty, didn't help me reach more teeth.

Reach Plaque Sweeperand Reach Interdental: I tried the "Full Head" sizes of these brushes, which tainted them for me. I'm not a fan of the "huge head" school of brush design, and both these heads span four or five teeth at once. This trend is understandable in brushes from toothpaste manufacturers (the huge-headed Aquafresh Flex Direct, for instance): Bigger heads mean more room for paste. But Reach is from Johnson & Johnson, which, as best I can tell, makes no toothpastes. Go figure.

The Plaque Sweeper, like many recent brushes, has a single, taller tuft of bristles at the tip of its head to clean "hard-to-reach back teeth." This tuft did not help me reach my back teeth—at least not accurately. Instead, it got in my way, bumping my gums, too bulky for fine cleaning. Ditch these SUVs and get something with better handling.

Crest Extender:"Gentle Extender Fibers extend beyond the rippled bristles," says the packaging. Think of your regular toothbrush, then add a few sparsely placed bristles jabbing up a quarter-inch higher than the rest. Unsettling, yes? These "Gentle Extender Fibers" poke right into your gums. I would have called it the Crest Intruder. Maybe the Crest Violator. Just looking at it's terrifying. This was the worst brush I tried.

Colgate Navigator: The top half of this brush head flexes independently of the bottom half, much like a segmented vehicle. Ask yourself: Do I want to brush with a segmented vehicle? When you flex out the top, it's a completely different angle from the bottom and brushing a separate tooth entirely. Maybe it saves time by brushing two surfaces at once, but this technique affords little control over bristles—you have to guess where they are. Also, I predict the rubber flexpoint will lose elasticity long before the bristles are dead. A poor entry.