One differentiator amongst electric toothbrushes is the type of movement the brush head makes. Rotating brush heads spin 360 degrees around while rotating-oscillating heads oscillate from side to side, not making a full circle. Sonic toothbrushes vibrate from side to side at a very rapid speed. While there are studies -- mostly sponsored by electric toothbrush manufacturers -- that claim one type or another is most effective, experts say that they all are effective, and the best one is ultimately a matter of personal preference. In other words, if you'll use the electric toothbrush to its full potential and it's comfortable for you to use, that's the type you should choose.
If you're skeptical about how well you'll like an electric toothbrush, or are leery of spending even $35, much less upwards of $150, we highly recommend picking up a and giving it a spin. Obvious puns aside, this basic toothbrush gets hundreds of owner reviews that match or exceed those of the much more expensive Oral-B and Sonicare rechargeable toothbrushes.
Philips Sonicare DiamondClean Rechargeable Electric Toothbrush is a higher-end model of toothbrush in Philips' lineup. It is based on earlier Sonicare toothbrushes in that it features a vigorous, vibrating head that helps force toothpaste into areas that are difficult to reach with manual toothbrushes. Its added features include pre-set brushing modes for different styles of cleaning (including a gentle one for sensitive teeth or gums), timers to ensure required brushing times are met, and multiple charging options. This latter function includes USB charging for travel or a home stand. The brush head uses diamond-shaped bristles that further help access teeth and gums, and the heads are replaceable and can be simply snapped on or off of the base. The additional features of this model make it more expensive than similar basic Sonicare models.