Ultrasonic toothbrushes

My take from all the above interesting discussion - whilst not reading every link - is that perhaps the purpose of the 'special toothpaste' may be to promote the formation of micro-bubbles rather than just bubbles, which then fulfil the function of cavitation and hence cleaning. (what is the pH of this toothpaste ? ) A similar effect, perhaps, to my adding 5ml of dish-washing-liquid in my domestic ultra-sound cleaning tank which apparently lowers the surface tension of the water thus promoting the formation of more numerous, smaller sized bubbles.
DaveD

Dave, I thought (before reading MichaelG's credible hypothesis about foaming) that Ruppel's SEM image must be of a solid structure and hydrated silica seemed the best candidate given that it's odd, amorphous stuff. Maybe I should have said 'most' rather than 'only'. Do you see an alternative if the image is of a solid in the toothpaste?

The doggy utrasonic toothpaste is indeed peppermint, which our dogs detest. We also have enzymatic (non-ultrasonic) dog toothpaste which is flavoured with 'poultry extract' - I try not to think too much about that means! Problem is they like it so much that they want to eat the toothbrush.

Sadly I didn't get the opportunity to test the brush on rust today but I did look up ultrasonic derusting in case it was a crazy idea. It seems that it should work - I'll give it a go when I can.

pgk - I reckon you could be onto a winner with your quinoa and goji berry idea. But:

The pet food manufacturer looking for new flavour ideas wasn't keen on my suggestions of Robin with Mouse flavour.

Over my dead body mate.

Robin

Edited By Robin Graham on 02/09/2019 01:32:24

Edited By Robin Graham on 02/09/2019 01:37:20

The ultimate in recycling?

You're probbaly aware that pelleted dog/cat food is an extruded mix that has the flavour sprayed on at the end of the process. They call that flavour 'digest' and while one hopes it's steam produced and analagous to boiling up a chicken carcase (or whatever) for soup then i guess the best that can be said is that its no worse than a turkey twizzler.

As another light hearted but true comment: we were given trial cans of venison cat-food which was actually god stuff asa novel protein for possible allergy cases. As usual we got sent an awful lot of cans to give away early December. I put a sign up "Feed your cat Rudolf for Christmas"

pgk

I always thought "mouse in a can" would be a viable idea.

Resurrecting this thread:

About 17 minutes into this: **LINK**

The Secret Life of Waves: www.bbc.co.uk/iplayer/episode/b00y5jhx

there is a short piece at University of Southampton, which may be relevant.

MichaelG.

Thanks for that Michael - interesting stuff. Keen as I was I didn't do my 'rust removal with an ultrasonic toothbrush' experiment because on reflection I thought domestic disharmony might ensue. It turned out that dog had a rotten tooth which has now dropped out - whether by nature or with the assistance of ultrasound I don't know. The animal is now chomping happily and the toothbrush has become redundant - it'll find it's way to my workshop I expect. In due course.

Robin

Probably throwing the thread somewhat off topic, the implosion of bubbles can be quite damaging, or effective, depending on the context..

The manufacturers of engines with wet cylinder liners had problems with what was called "waterside attack". This caused the cylinder liner to become porous, allowing coolant to make its way into the sump, via the microscopic holes in the liners. The problem was that as the piston reversed direction at top and bottom of the stroke, the skirt slapped the wall. This caused the coolant to cavitate, presumably because of minute deflections of the liner. When the resulting cavitation bubble imploded, it knocked the ferrite out of the liner.

One solution was to move the gudgeon pin off the centreline of the bore, to reduce the slap. Others chromium plated the liners, but ultimately the cavitation still made its way to the liner!

So US should be a good way to clean Fido's teeth, as long as not overdone. Possibly, water would be an effective conveyor of the US pulse, since this basically the main constituent of some US cleaning baths.

Give a product a fancy name and you can sell it for a vastly inflated price.

Or am I a cynic?

Howard

I think it’s time to revive this thread:

The Royal Microscopical Society has launched a YouTube channel, and the videos include this ultra high speed video of cavitation bubbles : **LINK**

https://youtu.be/K266mOgGYqg

MichaelG.

In the 60s there was a cat food called (IIRC) 'Dine' which was a canfull of silvery compressed whole fish in jelly.

Fluff loved it, but parents wouldn't buy it having seen (and smelt) it once.

That's amazing Michael. I see that the work dates from 2015 - have further advances in speed been made since then?

Apart from the astonishing microscopy it's interesting to see how the cavitation pattern changes with distance between the active and 'passive' elements. Maybe I should send these guys a sample of dog toothpaste!

Do you have any references to the original research? Couldn't see anything on the (obviously fledgling) RMS site.

Robin.

.

I found this page, Robin : **LINK**

https://www.birmingham.ac.uk/staff/profiles/clinical-sciences/vyas-nina.aspx

... but haven’t yet followed-up the list of her publications.

MichaelG.

.

Edit: Here we go:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4775067/

Edited By Michael Gilligan on 13/06/2020 23:31:28

My company used to sell Ultrasonic baths - I'm not an expert in this area though. From what I can remember, plain old water worked just fine. Some additives would compliment the the cleaning through chemical action acting alongside the cavitation while others would reduce the cavitation. Can't remember which now as its around 25 years ago.

With regards the damage ultrasonics can do, a simple test to ensure the bath was working was to dip a piece of aluminium baking foil in the bath for a couple of minutes. If the bath was working there would be pin holes punched in the foil by the cavitation.

Robin,

Here are some details about the camera they used: **LINK**

https://photron.com/wp-content/uploads/2014/07/FASTCAM_SA1.pdf

MichaelG.

.

https://photron.com/

Edited By Michael Gilligan on 14/06/2020 10:37:08

Thanks Michael. Pretty impressive technology. It looks like Dr Vyas is still working at Birmingham Uni - I may contact her to enquire about the influence of cavitation media. As she works in Dentistry it must be something that they have considered. I'm sure there must be funding opportunities from toothpaste manufacturers!

Dog owners might be interested to hear that the ultrasonic brush/toothpaste combination appears to have worked - the animal is munching happily again. However it's possible that she may have had had a rotten tooth which fell out in the course of nature. Perhaps stimulated by ultrasound - we'll never know.

Robin

I have discussed this with my two Red Setters as to what type of toothpaste they would prefer, and the answer I got [more or less ] was "What the hell is wrong with a good bone"?

Since it,s hard enough to brush their coats, I hate to think what it would be like to try brushing their teeth !