Post-Operative Endodontic Flare-ups (Part 1 of 2)
I want to use this blog to describe the endodontic flare-up (part 1) and how we can manage the situation (part 2).
The definition of a flare-up as offered by the American Association of Endodontics Glossary of Terms states: “A flare-up is an acute exacerbation of an asymptomatic and/or periapical pathosis after the initiation or continuation of the root canal treatment.” Or more simply stated; a patient develops strong pain and/or swelling following root canal treatment. I think it is the flare-up that is the feared outcome by the patients when they express their concerns about root canal therapy. A very common question that we field daily, “How will I feel after the treatment today?”
Certainly if you have performed enough endodontic procedures you will be aware of the “post-operative flare-up” condition. We all have a bag of negative emotions when a patient experiences a flare-up situation. Feelings of empathy, concern, sorrow and the strong want to make everything better. Those feelings never change regardless of how well we can manage a flare-up situation or how long you have been in practice. Certainly we in this office feel the same. It is just the nature of people to worry about others especially when they are under our care and they have come to us for help.
With part 1 of this blog, as well as with the upcoming part 2, perhaps you can take away some tips, or at least the understanding that you are not alone when you have these experiences in your office.
I will start by listing what I feel there are two important things to know about a flare-up condition:
1. It occurs in a low percentage of endodontic cases (~5%)
2. While we know reasonable well why a flare-up occurs, we cannot predict very well when or who will feel a flare-up condition.
Let me focus on the second point first. It is important to know that regardless of tooth presentation, we cannot determine who might feel a flare-up following treatment. For example, I can treat 10 maxillary first molar cases with the same presenting diagnosis, same presenting clinical conditions, and I will not be able to predict which, if any, of those 10 cases will experience a flare-up post-operatively. Chances are that none of them will (95% chance). But when I call on my patients the next day it is possible that one will have a flare-up and the others will have minimal symptoms. Why in that scenario with all the same presenting conditions would one patient experience a flare-up and the others not? The answer is simply that we do not know specifically why. Ultimately the contrasting outcomes can lead to error in judgment of the cause-effect relationship of treatment and flare-up conditions. Perhaps it is the immune-competency of that patient, perhaps it is the specific microbial content of that canal system, and perhaps it had to do with the endodontic technique or the psychology of each person’s personal reaction to pain situations. I’m quite sure that all of those have some contributory effect, but again if all conditions are equal, why one patient and not another. I have worked with patients that have had many endodontic treatments that were smooth and simple, but one of them resulted in a flare-up. It is the same patient with the same immune response and all teeth had the same presenting diagnostic condition. As mentioned, there are a lot of question marks and few definitive answers which leave us feeling frustrated as we very much want to protect our patients to the best of our ability.
Even though we cannot predict which patient may experience a flare-up and another person will not, we can give reasonable explanations as to why those patients develop this situation. It seems to me there are really two main reasons why a flare-up will occur; 1. Mechanically pushing necrotic/pulpal debris into the periradicular tissues, 2. Iatrogenically over-instrumenting the canal space beyond the apex. There are a few other reasons, but they are more of a fringe category. In either instance though, the periradicular tissues are reacting to the debris, bacterial content, and/or traumatized tissue with an extreme inflammatory response. In these cases the patient’s immune response was unable to overcome this bacterial challenge. These are complex cellular-level reactions involving immuno-regulation and mediators. Those are advanced discussions that are certainly not appropriate for this simple blog. But the point is that these are the generally accepted and primary reasons for the flare-up reactions.
If we could absolutely determine flare-ups to result from debris pushed into the periradicular tissue space during mechanical debridement, than it certainly makes sense that these presenting conditions of pulpal necrosis and retreatment would result in higher rate of flare-up. This should be logical because these cases have active, virulent bacteria intra-radicularly vs. a tooth with pulpitis conditions where the internal bacterial count is either non-existent or very low. Not only has it been our experience, but many clinical studies support the finding with teeth that are pulpally necrotic (5-7%) vs. teeth with irreversible pulpitis (1-2%). To take this a step further and apply it to retreatment cases, we again find an increase in flare-up incidence. Some studies of retreatment cases have reported up to just over a 10% chance for a flare-up. Anecdotally, we have had the same experience in our office. Again this makes sense given that retreatment cases are often associated with more resistant micro-organisms when compared to a primary endodontic infection (ie. non-retreatment cases). Those resistant and virulent bugs can and will be pushed into the periradicular tissues at some point during the treatment phase.
OverFills and Flare-ups:
I have been asked many times if overfilling of the obturation material will lead to post-operative flare-ups. My answer depends on many factors though. For example, if the RCT was done in a single visit than we cannot determine the flare-up is from an overfill because all of the other steps that occurred during that treatment time. The overfill is just one part of the treatment process that all occurred while the patient was numb for one visit. Furthermore, it does not take into account the pre-operative condition of the tooth. Another scenario would be if the tooth was obturated and overfilled at a 2nd or perhaps 3rd appointment. I would assume in these cases the tooth has been properly medicated and the tooth is completely asymptomatic. In that case we have limited some of the other factors (pre-op condition, bacterial concentration, etc) and we might be able to make a claim of a flare-up from an overfill. In this case I feel the amount of overfill and location could influence the post-operative discomfort. However, I very rarely see a true flare-up at a 2nd or 3rd appointment. That being said, I also do not see many overfills either. Perhaps it is possible, but my experience with tracking overfills as it relates to flare-ups is very limited.
Hopefully this blog will give you some bits of advice or simple knowledge as to why you see flare-up situations. They are stressful for everyone involved. Stressful for the patient because they are worried, and stressful for the clinician because we care for the well-being of the patients. But remember two more very important things; they do resolve and they are not indicators of endodontic failure. A patient that has a flare-up has the same expectation for long-term endododntic success as a patient that does not have a flare-up. What is perhaps more important though is managing the flare-up, encouraging the patient and arriving at a successful outcome. We will talk of the flare-up management in part 2 which I hope to have completed in the next few weeks.
Thanks for visiting us at Tri City and Fallbrook Micro Endodontics of San Diego, CA.