An article today in the Wall Street Journal covers the controversy due to Ultreo claiming, in the past, that the ultrasound action creates bubbles that clean plaque between teeth. Oral B brought a suit against Ultreo because of the claims, so they've toned down their marketing claims.
However, some dentists who have tried it still recommend it to their patients because it's action is gentle and makes the mouth seem especially clean. In fact, AT:HT reader Carol highly recommended the Ultreo.
The Ultreo retails for $170 including travel case and charger.