Hi Steve,

  Thanks for the welcome.  I'm surprised that I'm the only dentist
here, as I've met a number on the net.  Woodworking is a "natural" for
us as it's not very different from what we do all day.

> After a
>second or two of being surprised and wondering what on earth dentists have
>to do with files, I then remembered that they're quite the common and
>important dentistry tool.  (It was obvious, after all, only I hadn't ever
>really thought about that before.) 
    If you ever come across this paper I'd love to see it.  The
instruments we call files and rasps have nothing in common with
woodworking files and rasps.  Dental ones are cutting instruments used
in root canal.  They are round,  and tapered to a fine point towards
the end.  Stainless steel files are made by twisting a square wire.
The corners of the wire are the cutting edges.  You insert the file
into the canal and file the sides of the canal by pulling the file up.
Rasps are very similar (I don't use them as they have a greater
tendancy to break) but have more of a conical shape.  The newer
nickel-titanium files are more flexible and are cut out of the wire as
oposed to twisted.  The latest instrument of torture on the market is
the rotary nickel titanium files.  Interestingly, the ywork like
planes and shave the walls of the canal as they rotate.
   The closest thing we have to a wood file or rasp is the diamond
drills that we use.  They abrade like a file (I know some people refer
to a file as cutting but we make a distiction in that a diamond drill
abrades as opposed to a carbide drill which cuts).
  If you ever pass through Brampton, Ont., I'd love to give you a
personal demonstration :-)

Lawrie
				
>
>Am I being silly, or is it really something folks in dentistry do get
>into in that much detail?
   We don't usually discuss this type of thing at dinner parties :-).
I just happened to have taken a course recently on the new rotary
intruments.