As the title of my article denotes, some common knee-jerk decisions that a clinician may make because they seem to promise the fast, easy way to handle an endodontic failure are sometimes not the real solution. I am not necessarily referring to an extraction, although that might be the most predictable attempt at a solution, one that in turn has probably the more involved post-operative treatment, such as an implant or bridge.
Getting right into the nitty gritty, consider the apicoectomy. When a tooth presents that is endodontically failing with a post-and-core and crown, an apicoectomy might be immediately suggested because it’s easy and leaves the coronal aspect of the tooth intact. No porcelain fractures or undermining of the crown. No new post or new crown. Just a quick, easy surgical procedure done by your friendly neighborhood endodontist or oral surgeon. However, before choosing this option one must first explore the cause of failure fully to determine whether an apicoectomy is the appropriate choice. Additionally, the tooth location and anatomical considerations, such as the maxillary sinus and mandibular canal, must be looked at carefully. Patient expectations are to be considered, and of course the risks of the procedure and alternatives such as disassembly and retreatment or extraction should be fully discussed dento-legally.
The question becomes, is it more prudent to do a retreatment than to surgerize? On a lower molar apicoectomy, where a fair amount of bone must be removed to localize and identify the apex and achieve the proper root bevel, it may be more conservative to do a more predictable implant. If the proposed apicoectomy fails, it’s just that much more bone regeneration and grafting that has to take place before you can place that implant. If a retreatment is possible, then that would be the best alternative if the canals you are retreating are negotiable to the apex. Again, the cause of failure is key. A missed MB2 in an upper molar is the most common cause of failure. Surgery would be unnecessary if a scope had been used along with a CT scan during the original treatment. Using copious amounts of EDTA irrigant to open calcified apices and lateral canals is also not a bad idea both during the original RCT and retreatment. Look: there will always be failures and thus the decision to retreat, surgerize, or even extract.
Here are a few examples of fixing the problem without cutting soft tissue.
In the first case, the problem was just a simple missed MB2. A conservative access and a microscope to identify the canal and voilà, tooth fixed. (Figures 1 and 2).
In another case, an upper bicuspid that had been restored with a post-and-core and crown was symptomatic and had a PAR. A CT scan revealed a missed palatal canal. I opened a conservative access, followed the post head to the pupal floor, and expanded slightly to the palatal. Having uncovered the orifice and canal, I then treated them and resealed the coronal access. No post removal was necessary, and the crown was left intact. (Figures 3 and 4). Happy patient, happy referrer, and, of course, happy endodontist.
And, last but not least, a lower bicuspid (#28) with a not-so-nice endo and carbon-fiber post. With a microscope and an ultrasonic tip I blasted out the post and, using the CT scan and scope for guidance, I found and treated the missed lingual canal, avoiding an apicoectomy or extraction (Figures 5 and 6).
So, my fellow colleagues and valued referrers, there are a few conservative alternatives to consider when dealing with an endodontic failure and thank all the Gods if we are all doing endo correctly the failure rate falls to 5 to 6 percent. Thus, if I’m doing my math correctly, endodontic treatment can have a 94 to 95 percent success rate.
July - September 2013