Time to return to technical subjects! Been philosophizing a lot.
Pulps of teeth calcify. Meaning the cells in the living tissue inside our teeth lay down more hard tooth structure, and so they get smaller. This happens throughout life as part of the aging process. My dental school X-rays, for example, which I still have in the office somewhere, show larger pulp spaces than my X-rays do now. Simply because I'm older.
More detailed info here:
And pulps really get smaller when teeth are challenged by decay or fracture.
Still, they calcify from the crown down. Meaning that if we need to perform root canal treatment, finding the tops of the canals may be difficult, but once we find 'em, they're going to get larger the further we go in to clean them of infection.
Here's a view from above (in the Microscope) during root canal treatment:
This is what I call "the smiling monkey" view, with two canals filled and one cleaned but not yet filled. Imagine if these were just tiny, tiny crevices with just a slight darker color to indicate where they are. That's often the challenge we face initially, as we start root canal treatment.
But as I said, if we can find 'em we can clean 'em. Usually. Every once in awhile, we pass into a canal and get blocked part way in. Like this:
The light lines are Resilon, the material that fills and seals the part of the root canal system that I cleaned. You can see that I didn't get to the end of the root. I couldn't. I felt like all my instruments were hitting a solid wall of granite at a certain point in the root canal system. Nothing I did would pass through it. Now... Note the dark halo in the X-ray that surrounds the tip of the root. This indicates less bone density, which indicates where the worst of the infection is.
Not getting to it is a bad thing.
And yet. I've been around the block a few times by now. I know the value of patience.
After a month and a half or so, we brought our patient back for an additional treatment. I've found that if we "go back in" after some time has passed, the blockage is usually astonishingly easy to bypass.
And so it was:
This endodontic treatment ended up being the most predictable and seamless procedure I did that entire week.
Why are these "blocked" root canals easier to treat on a second try? I've never heard a detailed, scientifically sound explanation. Perhaps we dentists have blocked such canals ourselves, with dentin chips that we create in our instrumentation. This is a known issue; instrumentation debris forms a sort of microscopic mud or plaster that can fill a canal and impede our instruments. But in this case, I remember hitting the wall with the very first pass of my tiniest instrument, so I have my doubts about debris being the reason. Still, perhaps it was.
In any case, a second attempt at treatment (at no additional fee, we're still trying to get an acceptable result for our patient!) is almost always successful at getting past blockages in root canals. Never give up endodontic treatment without a good fight!