I too wondered if the Ultrasonic brush killed good cells as well as germs.
Also - get this skeptics - a red light glows but ....  how do you know
that the 1.6 mega Hertz head is working.
--------------------------
I bought the Sonicare toothbrush, too at $150.

It vibrates at 30,000 cycles per second just at the upper range of human
hearing. In fact after you turn it off you can still hear it for a while.
Apparently my ear or all human ears have a 'false memory'.

Seems to me that the brush would destroy gum tissue. The instructions say
just barely touch it to the teeth. Sounds risky to me. Also it made quite
a mess. You are supposed to use a gel and keep it wet, so you have to keep
a large reservoir of toothpaste and water in your mouth.

-----
And the ionic brush. The battery is said to last 1 year. There is no
on-off switch. It stays on all the time. Howd'a you know how long it sat
'on' in the store before you bought it?

J >  I too wondered if the Ultrasonic brush killed good cells as well
J >  as germs.  Also - get this skeptics - a red light glows but ....
J >  how do you know that the 1.6 mega Hertz head is working.
--
 Those things are supposed to operate at 1.6 MHz??  Then why not hold
 the head close to any AM radio and turn the dial to 1.6MHz.  
 You should get some sort of a signal if those claims are correct...

 * Ron Roth
---
 * RoseReader 2.10b P003228 Entered at [CRS]

Good questions.  Since my dental hygeinis tuses an ultrasonic toothbrush
fo my routine cleanings, I'll try to remember to ask them the next time
I'm there.

My guess is you close the circuit by wetting it with saliva.  So,
if it's sitting in the store immersed in a pool of spit--don't buy it.

--
--
DS Caprette
"There's a little truth in all jive, and a little jive in all truth."
                                  -- Leonard Q. Barnes

You might be able to feel 30 KHz, but I don't think anyone can hear
it; even being able to hear a 20 KHz tone is quite unusual.

Unless you're a dog.

  -- David Wright, Hitachi Computer Products (America), Inc.  Waltham, MA

     but you're free to disagree, you poor deluded creature
     "What the hell are you doing???" I screamed, in my best Father of
      the Year voice.  -- Jack Douglas

My dentist showed me a report from one of his dental magazines in which
several toothbrushes were tested.  The "ultrasonic" toothbrush is
COMPLETELY ineffective, except when you read the manufacturer's own
self-serving test results.  It is simply not powerful enough to do
anything, and the frequency is wrong (in the megahertz band rather than
kilohertz, which is where dentists' OWN ultrasonic instruments operate.

In fact, the company is not allowed to advertise it as anything but a
MANUAL toothbrush with an ultrasonic assist.

"Sonic energy" brushes, which operate at a frequency sufficient to cause
mild cavitation in liquid, rated highest.

Best sells them for $99.

No, the Sonicare vibrates around the frequency of middle C.  It says so
right there in the manual.  That's around 300 Hz.  You must be thinking
of a different one (or maybe there's a new model?)

Besides, 20 KHz is the upper limit for most humans.

Actually, 30 KHz is, I recall, about the right frequency for dentist
ultrasonic instruments.

--
                                           /|
Alex Matulich                      __.  __=#||  ___   _o--

                                \____________________________\

: >I too wondered if the Ultrasonic brush killed good cells as well as germs.
: >Also - get this skeptics - a red light glows but ....  how do you know
: >that the 1.6 mega Hertz head is working.
: >I bought the Sonicare toothbrush, too at $150.
: >
: >It vibrates at 30,000 cycles per second just at the upper range of human
: >hearing. In fact after you turn it off you can still hear it for a while.
: >Apparently my ear or all human ears have a 'false memory'.
: >
: >Seems to me that the brush would destroy gum tissue. The instructions say
: >just barely touch it to the teeth. Sounds risky to me. Also it made quite
: >a mess. You are supposed to use a gel and keep it wet, so you have to keep
: >a large reservoir of toothpaste and water in your mouth.

Also, buy those big, 10-gauge cables to connect it to the DieHard.
It works a lot faster.

GMS
http://www.svs.com/users/gmark

You folks are missing a bet.  Uncle Al uses the Tessie, a
4-dimensional temp{*filter*}displacement toothbrush.  It sends plaque and
whatnot foreward in time 75 years, when you will have no teeth at all (or
not care one way or the other).  When the present muck from your mouth
arrives, you merely expectorate.

Pilot models were developed some years ago, but minor glitches had the
stuff issuing forth from the mouths statues in churches and on Hindu
altars.

--
Alan "Uncle Al" Schwartz

http://www.***.com/
"Quis custodiet ipsos custodes?"  The Net!

(Uncle Al has been Officially convinced to "voluntarily" shut down his
homepage in February.   You can own his complete 529 essay collection.  
Surf by before it dies!)

The Sonicare operates 30,000 strokes per minute not per second.  This
would equate to 500 strokes per second which may mean only 250 cycles
per second.  There has been no clinical evidence that the "sound
waves" generated by the Sonicare are of any benefit.

Your hygienist is probably using an ulrasonic scaler rather than a
toothbrush.  The scaler cleaning tip is made of metal and the
utrasonics are used to vibrate the metal tip at high speeds for
knocking hardened deposits off of your teeth.  The ultrasonics waves
themselves do not do the cleaning, but rather the mechanical action of
the metal tip.

: >I too wondered if the Ultrasonic brush killed good cells as well as germs.
: >Also - get this skeptics - a red light glows but ....  how do you know
: >that the 1.6 mega Hertz head is working.

: My dentist showed me a report from one of his dental magazines in which
: several toothbrushes were tested.  The "ultrasonic" toothbrush is
: COMPLETELY ineffective, except when you read the manufacturer's own

I find it helps me navigate in the dark.

GMS
http://www.svs.com/users/gmark

: >Good questions.  Since my dental hygeinis tuses an ultrasonic toothbrush
: >fo my routine cleanings, I'll try to remember to ask them the next time
: >I'm there.

: Your hygienist is probably using an ulrasonic scaler rather than a
: toothbrush.  The scaler cleaning tip is made of metal and the

But he only needs 'em for really fast fish.

GMS
http://www.svs.com/users/gmark

Arf, Arf,  Arf arfarf arf arf arfarfarf  arf arf ARF!
( Translation - my teeth are clean )

--
James D Buch            "I don't study anything.  Well,
NB Research              I study porosity and surely, there
Costa Mesa, CA           is nothing to that!  Is there?"
714.645.9178