I'd think twice about the Sonicaire if you have old fillings or Amalgams hanging around. The Sonicaire caused me to have trouble with 'em a few weeks after I started using it, and I've had problems ever since. I'd be more likely to use the Sonicaire to clean my jewelry.
Also another use for the Waterpik: I have used it *on its lowest pressure* to irrigate ears and remove stubborn wax, also.
I get much better results than with either of the above brushing my teeth with the good old hand toothbrush, using baking soda.