If you get the manual of your device you probably will read that small electrical appliances are OK as long as "THEY ARE PROPERLY MAINTAINED". This is very tricky, while I was considering to have a ICD, I checked with a friend that is electro engineer, and the problem is that virtually ANYTHING wise a loose connection, can produce an electromagnet field that can affect it.
And nobody knows how to check the "properly maintain device".
Jesus
I have a device also, and the most worrisome equipment, according to the manual, is magnets. I live within walking distance of one of the biggest hydroelectrical Dams in the world, and as long as I do not go on a tour of the Dam, I get along fine. Otherwise, my device could be rendered useless, or it could cause the device to fire for no reason.
Also, cell phones are not supposed to be within 12 inches of the device, or the same effect as above may occur.
So, if your teeth whitening device has a magnetic drive of some sort, then I would advise not to use it., but rather opt for teeth whitening strips, or something comparable.
Hope this helps.