From: Terry Pannkuk
Sent: Wed 2/1/2006 17:46
To: ROOTS
Subject: [roots] Separated instrument: The Ghost

This was a freaky instrument separation I had yesterday.  It’s been a long while since I’ve had this happen and I’ve never
had one break like this.  I think Herb Schilder’s ghost caused it to separate since he hated rotary files. J  This male
patient had a somewhat challenging maxillary second molar with two separate MB1 and MB2 systems with a long sweeping 90
curve.  The MB2 was way out into the mesial marginal ridge and the dentist who just made this crown 2 weeks ago didn’t
have a chance of this not being an exposure.  After extending the access, finding the canals and performing initial
coronal flaring, I began some mid-enlargement with the rotaries.  When removing the S1 Protaper from the access I noticed
it looked shorter.  I pressed the tip with my thumb and noticed it was also stiffer.  I then looked at it under the scope
and sure enough, the tip was gone.

I couldn’t believe it because I never felt it separate and I wasn’t even sure which canal it could have been, since I went
through all four canals briefly just to create space to place files for radiographic measurement.  I then went through
some recapitulations and thought for a moment it could have been in the MB2 but the 10 K-file was eventually placed to
length without any sense of an obstruction.  I recapitulated to the estimated working lengths on all four canal systems
and felt nothing.  I then figured it has separated outside the tooth at some point during the assistant transfer and
didn’t worry about it.  In a few minutes I placed the files in the MB1 and DB canals to get a radiographic measurement.  I
was shocked to see the separated instrument in the apical third of the palatal root.  It confirmed my theory that files
just don’t break on their own outside the tooth.   I went back, flared and recapitulated a series of files in the palatal
again and felt nothing.  I then placed a purple Ultradent tip down the canal and saw nothing sucked up with the flooded
irrigant.  I went through a series of Hedstrom files 15-60 sizes, felt nothing, and nothing seemed to come out.   I placed
files in the palatal and MB2 to get the final working lengths and the file was directly next to the separated instrument
in the palatal apex.   I continued to completely clean and shape the case with no sense of obstruction and finally took a
cone fit film and it was mysteriously gone.   It was a ghost.  I finished the case, never told the patient about the
mysterious apparition and figure I won’t bother mentioning my paranormal experience to the general dentist either.

I probably sucked it out of the canal at some point after loosening it with the Hedstroms.   - Terry





C00l case, good to know that even you have seperated files ;-) - Thomas

Terry, it is interesting that Dr Schilder hated rotaries. I thought so too, but then today, in lit, we reviewed a paper by
Shafer & Lau 1999, about the Series 29 concept. They quoted two references by Dr Schilder from the early nineties on this
topic where thay say he praised these files, and I think I either heard or read that he even designed the ProFile Series
29. Did he? - Marcos Arenal

They weren't rotaries.  He didn't like NiTi either but realized that Tulsa was going to design them the way they could
sell them.  NiTi and rotaries were the fad and that's what was going to sell.  There's a definite disconnect between what
achieves quality and what is popular.  Rob wrote an excellent detailed description of the issue from Schilder's
perspective.- Terry

Series 29 was Schilders' attempt to correct the "jump" that occurred when going from 6 to 8 to10 to 15 to 20. You often
see this when your #10 file goes to length but the 15 doesn't. Same with 15 going to length and 20 not going. Look at the
size difference between #10 and 15 or between a 15 and 20! Compare that to the minor difference between 30 and 35. Most of
us understand that for tough cases you need MORE files in the smaller range and less files once you get up above 20 or 25.

Another prpblem that he often quoted was that according to ISO standard of allowed .02 variation in size manufacture -
this could actually cause you to use a "thin" #10 file ( which is actuallymanufactured as an 8)and then follwo it with a
"fat" 15 - which is actually a 17.  That's why that "supposed 15 file" won't go.( Conversely - you can have a situation
where you are using a "fat 10 - actually a 12 and then following it with a "thin 15" - which is in reality a #13.  THAT
file will go easily.) Some have tried to address the problem by having "in between sizes" 17, 19 etc.  That just sells
more files!! Others have suggested actually cutting the file ends off to make a "file of in-between size". I've never
understood that - the tips would be dangerous and sharp..

Schilder's Series 29 was how he envisioned a file system with a consisted constant difference in file size - which
actually translated to less innstruments.  For those of us who new him well - Herb actually preferred the old carbon steel
files and reamers with used the old "0,1,2 3" size system - before Ingle started the move to ISO standards.

The funeral is tomorrow. Rest in Peace Dr. Schilder. Your legacy lives on -  Rob Kaufmann

thank you Rob, since this makes so much sense, I wonder why the S29 has not made the ISO standards obsolete in relation to
endod instruments; or has it? - Marcos

Nice description! For years we've dealt with inadequate files and adjusted them to our needs.  They  still suck; just suck
less, or more or less depending upon the case. .:):):)

I hope to see you there tomorrow bro!  I'm at  LAX about to board the red eye as we speak. - Terry

have solved the 10-15-20 sizing problems in my practice by adding just 2 files to my set up.  I added a #12 and #17 Flex-
O-file.  I use 06, 08, and 10 K-files followed by 12, 15, & 17 Flex-O-files before proceeding to rotaries.  Flex-O files
have safe tips to reduce ledging.

I tore up the ligaments in my "endodontic thumb" in a snow skiing accident in 98-99 and had to have reconstructive
ligament surgery a year later when it didn't heal.  I probably would not be able to practice without #12 & 17 files and
rotary instrumentation - Randy Hedrick