Buzz, wiggle ... and rinse.(Up front: news / trends / advice)(electric toothbrushes )(Product/Service Evaluation)

'Round and 'round is so square. Now electric toothbrushes oscillate, wiggle, and buzz. Many such electrics cost about $50 to $150, but Colgate, Crest, and Oral-B have introduced models that cost far less.

A dozen staffers who brush with nonelectric brushes volunteered to test each of four electric brushes--three inexpensive ones and a much pricier model that is widely advertised--plus their usual brush. All four electrics are advertised as able to clean teeth better than a regular brush does.

Our volunteers used each brush for about a week (to get used to it), left their teeth unbrushed for a day (to let plaque build up), then let a dentist we hired as a consultant examine their teeth. He scored the amount of plaque on specific teeth, asked each staffer to brush, then rescored those teeth to gauge a brush's plaque-removal prowess (plaque removal is central to preventing cavities and gum disease).

The bottom line. Even the most effective (and expensive) electric brush in our tests, the Sonicare Elite 7500, $140, proved no better than a regular brush costing $2 or $3. And every brush garnered at least one complaint about noise and annoying vibration.

What matters most, it turns out, is your technique and how long you brush. Toothbrush makers usually recommend two minutes. Therein lies one potential advantage of electric brushes: Our volunteers, who brushed for as long as they thought necessary, tended to brush longer when using electrics. In fact, all but one staffer liked power brushing enough to consider switching ...