Kase of the Month - Persistence is Key!!
Every once in a while it's good to be the hero. After all go ask Ironman and Superman their opinion and I'm sure they will agree. Failure of a prior root canal just happens. It can happen for many reasons as I pointed out in a prior case. So let me repeat for a brief moment. There are obvious reasons we may see either clinically or radiographically. Caries contamination for starters. A failed, well obturated with all canals identified RCT that has had long standing decay in the chamber is a good reason for failure and re-treatment. Pretty obvious!! Short fills, missed canals, lateral canals and under instrumented canals are all reasons for potential failure with the ability to retreat and resolve. Sometimes there separated instruments and sometimes there are post removals involved which require dismantling of the restorative. Obviously the key is diagnostics. Some are apparent and some not so much! For me a CBCT IS THE MOST DIAGNOSTIC TOOL WE HAVE AT OUR DISPOSAL. It gives us the blueprint for re-treatment direction. Using a microscope allows us to more precisely locate the cause once we have our game plan in mind.
So here is a case of tooth #19 which was endodontically treated years ago and now presents with a large PAR related to the distal root. The tooth had been crowned and a post placed in a distal canal and mesial canal and built up with a composite core. A CBCT scan confirmed the pathology location and also identified the cause. Apparently there was a missed DB canal which seemed to join the DL canal apically. My thought was to leave the post intact and locate and clean the DB canal. This is a clear example that in adjacent canals with a common apex, the unfilled portion will contain organic matter that will breakdown and contaminate the common apical section.
I tunneled down along side the post, found the canal and instrumented it completely. The patient was leaving in 2 days for vacation so decided to medicate and close temporarily. Placed on clindamycin 150 qid and hoped we nailed it. Well this was quite a large beehive we kicked and needless to say Murphy's Law of Dentistry kicked in. A large flare up which lead to an antibiotic change to Avelox 400 which led to an I &D which led to adding metronidazole to the mix. When the patient returned the following week he was still swollen with a pocket down the DB root. I reopened th case and got a ton of drainage. I decided to use a small suction cannula and evacuated the drainage until I was able to finally irrigate and dry the canal. I then threw all caution to the wind and obturated and reiterated the I&D and placed a drain which was removed 2 days later. The patient was pain free at this point. I saw the patient 3 days later and he presented with slight residual expansion, but the pocket on the DB was resolved, the I&D sight was healed and he was feeling great.
So this was a case where one might have jumped to an extraction more rapidly, but persistence on the part of the treater and treatee paid off heroically.