I have recently heard on the news and read articles about faulty electric toothbrushes.  The ones that are failing are specificly the Crest Spinbrush and Arm and Hammer Spin Brush.  Many of our patients have asked us about the safety of these and similar brushes.  As a dentist I would have to say avoid these particular brushes, but in general a mechanical or electric toothbrush cleans your teeth far better than any manual toothbrush.  Personally, my whole family uses a Sonicare toothbrush, while my children like the Colgate spinbrush because of their fun designs.  We have never had any problems out of either.  So I would recommend both as a dentist and a parent the Sonicare toothbrush first, then Colgate spinbrush.  Here is the FDA article so you can read for yourself. http://www.fda.gov/downloads/ForConsumers/ConsumerUpdates/UCM291863.pdf