Electric toothbrush braces). The Broxo Electric Toothbrush was introduced in the U.S. by E. R. Squibb and Sons Pharmaceuticals in 1960. After introduction, it was marketed in the U.S. by Squibb under the names Broxo-Dent or Broxodent. In the 1980s Squibb transferred distribution of the Broxodent line to the Somerset Labs division of Bristol-Myers Squibb. The General Electric automatic toothbrush was introduced in the early 1960s; it was cordless with rechargeable NiCad batteries and although portable, was rather bulky, about the size of a two-D-cell flashlight handle. NiCad batteries of this period suffered from the Memory effect. The GE Automatic Toothbrush came
Electric toothbrush have already been broken up by the ultrasound. Because of the similarity of the terms “ultrasonic” and “sonic”, there is some confusion in the marketplace and sonic toothbrushes are frequently mislabeled as ultrasonic ones. A toothbrush operating at a frequency or vibration of less than 2,400,000 movements per minute (20,000 Hz) is a "sonic" toothbrush. It is called "sonic" because its operating frequency, for example 31,000 movements per minute, is within the human hearing range of between roughly 20 Hz to about 20,000 Hz. Only a toothbrush that emits ultrasound, or vibration at a frequency greater than the upper limit