What is your budget? Top-rated electric toothbrushes can be expensive -- upward of $100 -- especially when compared to affordable manual toothbrushes. A good plan is to buy the best toothbrush you can afford, but that doesn't mean it has to be a top-of-the-line pick. Most manufacturers offer low-end models of their top performers. These are basically watered-down versions of the most expensive toothbrushes that work in exactly the same manner but have fewer bells and whistles.
Do you have a brush movement preference? Rotating-oscillating brushes perform slightly better than sonic brushes in professional tests, but experts say both do an excellent job of removing plaque.
How small (or large) is your mouth? The size of the brush head is important. Smaller brush heads allow greater access to hard-to-reach tooth surfaces and fit comfortably in small mouths, while larger brush heads can clean more surface area in a shorter amount of time.
How many people will be using the toothbrush? Some retailers offer bundles that include more than one toothbrush handle and/or multiple brush heads.
Will you be travelling overseas with the toothbrush? If you travel overseas for more than a few days at a time, you should look for an electric toothbrush that has a multivoltage charging unit.
Electric toothbrushes cost more initially than manual toothbrushes, but they also have ongoing costs that are important to consider. Like manual toothbrushes, the brush heads on electric toothbrushes must be replaced every three or four months. Replacement brush heads generally cost a bit more, however -- about $8 to $10 versus $3 to $6 for a manual toothbrush. Battery-operated toothbrushes also require frequent battery replacements.
To learn more, watch this About.com video on how to brush your teeth with an electric toothbrush if you have braces.