The Effects of Sonic Vs. Rotary Electric Toothbrushes

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Technological advances have turned selecting a toothbrush into a process requiring careful thought and consideration. The American Dental Association and the Mayo Clinic say that although proper use of a manual toothbrush can clean teeth effectively, electric toothbrushes make it easier to do the job well. In fact, ADA-sponsored studies have shown that patients who used electric toothbrushes more frequently had cleaner teeth and better gum health. When selecting electric toothbrushes, choices include rotary versus sonic toothbrushes.


When bacteria collect on tooth enamel, they come together and form a solid substance called plaque, which if allowed to harden turns into a yellow, crusty material known as tartar. When plaque and tartar sit on teeth for long periods, bacteria begin to wear away tooth enamel, creating cavities--the first symptom of tooth decay. Bacteria also like to settle into gum crevices, which creates gum disease. Early-stage gum disease is known as gingivitis. The primary purpose of a toothbrush is to break up and sweep away plaque to prevent these problems.


Electric toothbrushes were developed to increase the number of brush strokes per minute on a person's teeth. Dentists and electric appliance manufacturers realised that machinery could move brushes faster than a human hand, making toothbrushing more efficient and more thorough. Advances in technology led to the rotary toothbrush, which can spin at 3,000 to 7,500 brushstrokes per minute. The American Dental Association has concluded that rotary toothbrushes contribute significantly toward better dental health.

Sonic Technology

There's only so fast that a dial can spin safely, and researchers believe they have achieved that maximum with rotary toothbrushes. Sonic technology attempts to increase the toothbrush power by emitting sound wave pulses that cause water molecules in saliva to push against teeth, in effect turning them into additional toothbrush bristles. By employing water molecules as cleaning aids, sonic toothbrushes effectively increase brushstrokes to 30,000 per minute.

Gums and Crevices

Sonic toothbrushes have one distinct advantage over other toothbrush technologies--they clean more thoroughly between teeth and below the gumline. That's not to say that some of the better electric toothbrushes don't clean these areas. However, sonic waves travel where bristles have trouble reaching. Saliva and water go everywhere in the mouth, and sonic waves get them cleaning important, hard-to-reach places.

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