An electric toothbrush is not a modern invention –invented in 1954 as a toothbrush which plugged into the electrical outlet directly – and continues to be useful today.
Standard electric toothbrushes work by using fast, bristle motions over the teeth and gums, in either a circular or back and forth motion, to provide the cleaning action. An internal motor within the brush provides the power to move the brush head during use.
Modern electric toothbrushes come with internal rechargeable batteries or with an option to replace batteries periodically. Originally toothbrushes used metal connectors and sat in a base to recharge, but now they use induction charging which makes it simpler to charge them. The toothbrush sits in the base and charges from that position, rather than needing to be precisely slotted into place.
The number of oscillations by an electric toothbrush falls into the 2,400 to 2 million range per minute. The oscillations are barely audible, but the motor is likely to emit a sound during use.
Most electric toothbrushes are now sonic toothbrushes, with the technology has improved since the early beginnings of the product in the 1950s. Sonic brushes use a sweeping motion, which is different from other types. The number of oscillations is between 12,000 to 24,000, and there are models with 24,000-48,000 motions each minute. The sweeping motion is wider than with standard electric toothbrushes. Sonic toothbrushes are perceived to be an improvement over earlier models.
Ultrasonic toothbrushes are less common but are the next step up in innovation. Initially, the product only used ultrasound, but they now use ultrasonic waves on a 20,000 Hz frequency. Ultrasonic cleaning tools are authorised to operate at a 1.6 MHz frequency in the USA, which creates 192 million movements every minute.
The ultrasonic effect works by using sonic waves to break up bacterial chains present on the surface of the tooth and up to 5mm below the gums too. The vibration shakes the chains of bacteria from staying connection and destroys them. A newer sweeping motion has also been incorporated into some sonic toothbrushes because this has been found to get rid of remaining stubborn bacteria and bits of food.
The more advanced ultrasonic toothbrushes have not taken off in the marketplace as much as their sonic counterparts because the technology is patented which has prevented it being marketed widely. Ultimately, several major companies now focus on oral care products to compete with their lines of sonic electric toothbrushes.