Ultrasonic toothbrush

Today, they have evolved and based on the speed of their vibration, can be divided into three categories: electric, sonic and ultrasonic.

The most common frequency however, around which many scientific studies have been conducted,[4] is in the area of approximately 1.6 MHz, which translates to 96,000,000 waves or 192,000,000 movements per minute.

The first ultrasonic toothbrush, initially branded Ultima and later Ultrasonex by Sonex Corporation, was first patented in the USA in 1992 by Robert T. Bock,[5] the same year the FDA gave it approval for daily home use.

In 2008, Salton Corporation's new owners decide to exit the oral hygiene market and since then, several new companies started selling ultrasonic toothbrushes such as the Ultreo, Megasonex, and Emmi-Dent brands.

These regulations limit the power output of these devices to a level low enough to avoid raising surrounding tissue temperature by more than 1 °C.