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
Ultrasonic toothbrush have a fundamental frequency from 85 to 180 Hz (10,200 to 21,000 movements per minute), and that of a typical adult female from 165 to 255 Hz (19,800 to 30,600 movements per minute). Ultrasonic toothbrushes work by generating an ultrasonic wave usually from an implanted piezo crystal, the frequency of which technically could begin at 20,000 Hz (2,400,000 movements per minute). The most common frequency however, around which many scientific studies have been conducted, 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