At times when there is no clear cut terminology in dentistry we have to invent words or to add meanings to words to describe either a process or technique.
One of those words that we have had to define is 'probing'.
Generally to probe means to feel or test by feeling.
And generally that is what we do when we first put a file down a canal.
But what do you call it when moving apically into the canal requires more effort.
Sometimes the best way to describe something is in comparison to something else.
In this case that something else is filing.
The difference between probing and filing is this. In probing the canal is smaller than the file and in filing the canal is bigger than the file.
Thus, these terms are utilitarian, if not completely semantically correct.
If we were attempting to plumb the depths of a tank with a yardstick we would not call that probing we would call it measuring, so lets add one more term to our endodontic vocabulary and call what we do when a file drops to depth without probing or filing...measuring.
What we do when we simply drop a file in either to use the apex locator or to take a radiograph for measurement, we call "measuring".
If we have to work a file to a given depth, i.e. when we drop it in, it binds and will not go to the length that we intend, we will call "probing".
Once the canal is measurable to a given depth and we want to enlarge it, using a file that will fit, we call that "filing".
This filing can actually be reaming but for purposes here let's just call anything that enlarges an already probed and measured canal filing.
Now that we have the definitions out of the way, we can begin a discussion of the various kinds of probing.
In dental school most of us were taught a kind of probing that I call "lump-avoidance probing".
I will introduce you to a different concept, that of "lump-compression probing".