I bought some on ebay a couple of years ago really cheap. I told the guy what I would be doing with them and he gave me a really nice selection. I got 50 of 'em for about $15 or $20 as I recall. They're all new in original factory packaging.
Yeah, I bought a boat load of miniature end mills, drills, and burrs from ebay a couple years ago too. These dental burrs are smaller than even those. I go back every 6 months for a cleaning and another packet of burrs.
I bought actual dental burrs. I have a dental handpiece they go into, just like your dentist's high speed drill. Then I rigged up a HF regulator and used an HF blow gun with the tip removed for a foot switch. Looks funky but works great... or should I say, works a treat!
Oh, OK. Kewl!
Just don't get any bright ideas about doing your own fillings or root canal procedures.
NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO!