Sonicare will keep your teeth clean
I've used Sonicare toothbrushes for years, getting my first one after I was diagnosed with gum disease.  I don't really know whether it helps with gum disease -- I don't really think that any "ultrasonic" below-the-surface cleaning is going on -- but there's no doubt that the vigorous brushing (I think they say 33,000 strokes per minute!) keeps your teeth clean!  (By the way, this is my first time of buying this model.  I used to use their original model (the one with the straight-line brushes), but they no longer sell that model with the additional "30-second timer" (when you turn the brush on, it runs for 2 minutes; with the 30-second timer, you also get a beep every 30 seconds so you can brush a different "quadrant" of your mouth, which is very helpful).  This model was the cheapest one I could find that also had the 30-second timer.)  There's no question that after you've used a Sonicare, if you for some reason have to brush by hand again, you'll realize what a mere "lick and a promise" cleaning you were giving your teeth before!
Rating: 5 stars