I've posted about electric tooth brushes here for many years, every
two or three years. By now, hopefully everybody (including dentists)
understands the benefit of using an electric toothbrush over a
manual toothbrush.

I recently picked up a high end Oral-B model from eBay, a 9000
series. It was cheap, but a lesser (smaller and lighter) model for
the same price might have been a better choice. Unless you are
raising an NBA basketball player, you might want to avoid it. It's
big and heavy. That's just in case you intend to buy one over the
Internet where it's difficult to return things. They include four
motor settings on the 9000 I have... regular, soft, massage, and
polishing. In my opinion, the massage and polishing are a little bit
silly. I think much better would have been to use the last two
settings for the two different types of head action alone,
oscillating for one and vibrating for the other.

However long ago, Oral-B added vibration to the oscillation, so now
the brush head beats down against your teeth in addition to
rotating. The rotation is very good by itself, but I definitely see
the vibration as another major plus over manual toothbrushes. I
think one trade word for the Oral-B dual action is "3D" (they have a
Dual Action brush head, but that refers to the type of brush head
and not the additional vibrating motion).

If you're in the market for a new and improved toothbrush,
definitely go for the "3D" two/double/dual action Oral-B toothbrush.
I think the "3D" labeled brush is the cheapest, or maybe it's the
5000 series. The additional action is plainly stated in the
marketing. If you've never used electric, pick up any cheap
namebrand toothbrush and check it out. I used the cheap ones for
years, still better than manual.

Good luck and have fun.