I had a patient present to me this week complaining of pain and swelling associated with a lower molar. She had previously had root canal therapy and then apicoectomy performed by her dentist about 8 months ago. She was disappointed that symptoms had recurred as she had seen the dentist in her home country one month ago and he had told her the treatment had been successful, healing was proceeding well and that a crown could be placed. She told me that her dentist had told her prior to the surgery that she had a large lesion and that the actual surgical procedure had been very painful.
This case is a good one to base a discussion on case selection for apicoectomy. The first thing to note is that the quality of the original RCT is inadequate. One mesial canal is filled well short of the appropriate length. Additionally, the distal canal is poorly filled. There is also evidence that the composite resin restoration may be leaking. It’s reasonable to assume that the root canal was failing due to infection within the canals, and it has been clearly shown that this is the case for the vast majority of root canal treatment failures.
So from a purely endodontic point of view (disregarding alternative options or the influence of prosthetic factors), we have two main options. First, we treat the infection in the canal by undertaking RCT re-treatment. Secondly, we “entomb” the microorganisms in the canal and prevent them and their products reaching the periapical area by undertaking periapical surgery with retrofill.
In this case, we can see that periapical surgery has been undertaken, but no retrofill has been placed. Given the (very safe) assumption that infection remains within the canal, then simply resecting the apical portion of the root will not achieve anything of use. The canal will remain open and the microorganisms will continue to thrive within the canal continue to release products that induce an immune response in the periapical tissues. Unfortunately for this patient, their dentist has shown a lack of understanding of the cause of periapical pathology and needlessly put the patient through a surgical procedure. There may have been some healing of the lesion sue to the surgical procedure, but complete healing could not be expected.
A recent randomized clinical trial compared the outcome of apical surgery where either an MTA retrofilling was placed or the GP filling of the resected root was smoothed and no retrofill placed (Christiansen et al. 2009). The outcome was quite clear that placement of MTA retrofill provides a superior rate of healing compared to just leaving the GP intact. The study didn’t really go into detail as to the quality of the orthograde root fillings in the teeth, but in a situations such as the case discussed above, a retrofill is a necessary part of the procedure. For those of you who don’t have experience with preparing and placing retro fills, it is a skill that requires some practice and specialised equipment. This is especially so once you start to treat molars and teeth with isthmuses.
Without seeing the initial radiographs, I’d have to say that from a purely endodontic point of view, RCT re-treatment should have been considered prior to any surgery. This may have been successful in treating the infection alone, but if not, it provides a better chance of the canals being cleared of infection prior to the surgical procedure, and this then improves the chances of success of the subsequent surgery. Alternatively, apical surgery with retrofill performed by a skilled clinician might have been successful in this case.
Christiansen R, Kirkevang L-L, Hørsted-Bindslev P, Wenzel A. Randomized clinical trial of root-end resection followed by root-end filling with mineral trioxide aggregate or smoothing of the orthograde gutta-percha root filling – 1-year follow-up. Int Endod J, 42, 105–114, 2009.