Minneapolis, Minnesota ... June 30, 1994
Latest Update Saturday, January 17, 1998
One of the most frequent requests that I get is for a quick review of the parabolic funnel prep.
The basic sequence of files depends on the individual case but there are a few principles you should keep in mind.
Since we would not cause a ledge, no matter what the sequence of the files, the order of the files is simply the best and fastest way we have found to do the prep.
It is important to get a patent apex.
Only in this way can you be sure that you have a good seal at the apex.
None of these files should get stuck in the canal.
If they do, there are several possible reasons.
First, you might not have enlarged enough with the previous file.
Second, the canal may be curved.
Third, you are in another canal.
Note when holding a file in a hemostat or needle holder forcep, it doesn't matter whether that file is a sonic file or a hand file.
This is known as the McCombs modification or simply the McCombs prep.
This allows the 30 gauge needle which is .29mm in diameter to get within 1mm of the apex.
If you have difficulty getting a #30 to the 1mm point it may be necessary to go to the 1mm point first with a #25.
This makes the parabola, which is a pressure relief area.
The idea is to get this as close to the apex as possible without getting so close you endanger the apex.
In some curved canals or in cases where you have done a step back preparation, it is not possible to get close to the apex and the parabola is not possible.
E-mail your comments to drjack@BetterEndo.com