This patient reported a history of endodontic treatment in the Far East, then retreatment a few years ago. He ended up in my office because of a persistent parulis buccal to the tooth. I decided to retreat again, but had no real success in resolving the infection. It’s a rare two-rooted lower premolar.

We decided to do some exploratory/apical surgery. After mucosal reflection, I was able to confirm a vertical root fracture that started apically. This is probably partially because weakening of the roots from the amount of intracanal instrumentation this tooth has gone through over the years.

I was not able to apically resect the root to eliminate the fracture because of the complete loss of buccal bone and the short root that would have remained. The prognosis for this tooth is hopeless.

Not that I do one every week…

Here’s a case that was finished last year. Previous endo, post and crown. The tooth was symptomatic and demonstrated either apical external resorption, or more likely, some sort of apical surgery (the patient didn’t recall any surgery but that doesn’t always mean it was not done).

Anyway, the retreatment was started, the canal was medicated, the patient forgot to come back for a few months, xray then showed washout of the calcium hydroxide, but some degree of apical healing. Endo was finished; some apical sealer puffs can be seen.

The recall today shows progressive apical healing and resorption of the extra sealer.

This is a case of an upper central incisor on an 11 year old boy that I diagnosed with chronic apical periodontitis. I started the retreatment today and as with all my retreatments, I try to remove the obturation material (gutta-percha in this case) without solvents. Solvents tend to smear the gutta-percha around the canal walls and can actually make dentinal disinfection more problematic. I generally only need solvent for canals that have some sort of solid gutta-percha carrier in them (eg. Thermafil).

The previous endo looks not too bad. There are some spreader tracks visible, but length and density of fill are good overall. Unfortunately there’s a good chance the canal is much wider than the existing filling material shows. It’s a young tooth and an upper incisor to boot.

Once I started the retreatment I took instrumentation apically to a #60, was able to get a #80 to within a couple of millimeters of the apex (the apical curve was restrictive) and still I could see gutta-percha in the canal along the walls. This means that the canal was definitely very wide–it had to be if I could fit a large instrument to length and still not remove all of the existing apical obturant.

So I had to resort to a trick that I use in cases like this. I had to create a fish hook. The fish hook works better than a barbed broach and got the apical segment of gutta-percha out (the GP cone had a nice coating of pus around it). You can see where the previous instruments had carved the gutta-percha cone.

The tooth is currently internally medicated with calcium hydroxide paste for therapeutic purposes. It will be finished in a couple of weeks.

Here is a tooth that we redid an old root canal treatment on. There was plastic Thermafil in the distal canal that had previously been treated (I found an extra distal canal) and metal Thermafil in the mesial canals. The case was done over two appointments in order to medicate the canals therapeutically with calcium hydroxide paste.

Here is another recent case. Tooth 12 is a planned extraction. With a mobile crown and chronic infection, the root is likely fractured. Both 12 and 11 were surgerized years ago. An apical resection was done on 12 along with some curettage only around the apex of 11.

This pre-op shot shows a carbon fiber post too deep in the root of 11, with no obturation evident. The tooth had a parulis apical to 11 when I first saw the patient for consultation. A diagnosis of a chronic periapical abscess was established and endodontic retreatment was recommended.

The retreatment was completed over two appointments in order to medicate the canal for a couple of weeks with calcium hydroxide paste. During the first appointment, the post was removed and instrumentation was taken to a #120 file. Working length was established electronically and was found to be consistent over multiple checks.

The PA shows a significantly short obturation with a hint of sealer sneaking laterally towards 12.

What happened here? The most logical explanation is that the root was nicked and perforated during the apical resection of 12.

Should I have obturated to the radiographic apex? I could have, but I had a more reliable length to PDL space with my apex locator. As long as the canal coronal to the perf is disinfected and sealed, I expect the patient’s body to deal with any infection within the apical segment. Generally this happens via replacement resorption of the segment or via flow of blood or plasma through the perf and out the apex or vice versa.

Still, apical surgery is a possible adjunct whether or not obturation had taken place to the radiographic apex so this tooth will need to be monitored for signs and symptoms over the next couple of years.