to produce a hum in the audible frequency of human range (20 Hz to 20,000 Hz), it can be classified as a sonic toothbrush. Any electric toothbrush with movement faster than this limit can be classified as an ultrasonic toothbrush. Certain ultrasonic toothbrushes, such as the Megasonex and the Ultreo, have both sonic and ultrasonic movements. Oscillating rotating The oscillating rotating toothbrush is a type of electric toothbrush which was introduced by Oral-B in the 1990s. This type of toothbrush is not shaped like a conventional manual toothbrush. Instead, it is made of a small round brush head that oscillates and rotates to remove plaque. The shape of the brush head is very similar to the prophylaxis hand piece used by dental professionals to remove plaque in the dental office. This design enables the bristles to reach further into the hard-to-reach areas between the teeth to remove plaque. Some versions of the oscillating rotating toothbrush also involve a pulsating motion which enables a more three dimensional clean. The Oral-B iO toothbrush has a linear magnetic drive system. This system allows the concentration of energy to be at the tip of the brush bristles while using the oscillating rotating motion. The brush also allows for 3D tracking using artificial intelligence that connects the toothbrush with an app. This technology enables to the user to have instant feedback on their brushing efficacy and can track the data if the user wishes to bring the information to their dental professional for more personalized oral health instruction and education. Furthermore, the Oral-B iO toothbrush also has a smart pressure sensor which is electronically calibrated to let the user know if they are brushing with too much pressure, or not enough, and automatically adapts the oscillation speed to protect the teeth and gums when excess pressure is applied. The safety of oscillating rotating toothbrushes has also been studied. Oscillating rotating toothbrushes are proven to be safe as compared to manual toothbrushes and are safe for both the hard and soft tissues of the oral cavity. Sonic Sonic toothbrushes are a subset of electric toothbrushes with movement that is fast enough to produce vibration in the audible range. Most modern rechargeable electric toothbrushes from brands such as Sonicare, FOREO, and Oral-B fall into this category and typically have frequencies that range from 200 to 400 Hz, that is 12,000–24,000 oscillations or 24,000–48,000 movements per minute. Because