My No 3 had a root canal and crown. There was a 3/16 Inch circle between the three roots on the X-ray, and a dark line, about 1/16 Inch long on the x-ray. There was another small circle at the tip of one of the roots of #3. I could feel sensitivity in my upper right jaw, when taking a steep step, or changing my head position abruptly. I slap the back of my head lightly, to guage my progress.
#3 is the third from the back, upper jaw, Right side.
Extraction was recommended. So I had the tooth extracted, and there was a 3/16 Inch diameter bag of a substance, between the three roots, the Oral Surgeon said was an infection. The idea was that even if the infection could be cleared, that the crack in the root would continue to cause problems. A periodontist had evaluated the tooth for surgically cutting off a root, but felt that since the infection site was between the three roots, that mroe than one root might have been compromised.
I was told that root canals make the teeth more brittle.
So I still had some feelings, went back and the X-ray showed that there were remains of two roots, of #3, showing white-colored root canal passages in the roots. A less experienced Oral surgeon in the practice went back in, but decided not to drill further, because of the prxomity to the Sinus Cavities, next to the upper jaw.
A more experienced Oral surgeon went in a third time, and did some drilling on the jaw, and got out the two remaining roots of the #3 tooth, with root canals.
Apparently a good question to ask, before having a root canal in the upper jaw is, how close are my roots to my sinus cavities? Do you feel that there might be a problem with getting too close to my sinus cavaties, if an Oral Surgeon has to drill out the Root Canal Tooth, if the Root Canal Tooth goes bad?
Apparently some 10% of root canal teeth go bac, over time, in one way or another.
Found a Reference in Root Canals to Cavit Scan. Never had one. Seems to asess the jaw bone health.