The unique imploding action which is caused by the ultrasound destroys the particles and breaks up the membranes of bacteria and germs. The ultrasound implodes millions of bubbles every millisecond, while at the same time creating new ones. This continuous cycle goes on while the ultrasound is transmitted from the brush head. Actual "brushing", like with other toothbrushes, is not necessary! That"s what makes Emmi-dent so gentle and sensitive to your gums. Emmi-dent is a "No-Brushing Toothbrush", people who have receding or inflamed gums can breathe a sigh of relief - pain and irritation from brushing are non-existent. Great for People with Braces or Implants!!!!