A few years ago when I was still teaching at the dental school at the University of Toronto, a student ran up to me with this xray. The patient had been attending the faculty for treatment for years and had just been transferred to this student. The tooth was asymptomatic and there were no clinical signs or symptoms of endodontic pathosis besides this apical lesion.

The obturation was overextended in one canal, underextended in the other and there was a fairly large lesion. It also looked like there was still some cotton in the pulp chamber under the permanent amalgam.

The student wanted to know whether he should recommend endodontic retreatment to the patient. This is a fairly common dilemma in practice–an asymptomatic case with a lesion. The differential diagnosis is usually chronic apical (periradicular) periodontitis, on-going healing, or an apical scar.

Because we should be treating patients and not xrays, we do need to make sure that there is some evidence of pathosis before planning treatment. The approach that I generally take with these cases is to follow these teeth over time and see if either signs or symptoms develop or the lesion increases in size.

This particular situation was almost a no-brainer. The film above was taken two years prior so I asked the student to take a more current PA. He did, and this is what it looked like.

This turned out to be a tooth with a healing apical area. You can see resorption of the extruded gutta-percha has taken place. This case is also significant for a couple of other reasons.

First, pulp chambers with cotton or that are empty are often bacterial breeding grounds and with endodontic treatment that is less than ideal, bacteria will easily penetrate to the periapical area. Two, endodontists that are always blaming short fills for endodontic failure should review cases like this.

This case probably worked out (hopefully it will continue to heal) because it was done at the dental school. Although the quality of the final obturation and probably the quality of instrumentation was not ideal, the patient likely returned at least three or four times for the root canal treatment. That means lots of irrigation and disinfection. Because the case was done at the dental school, it also means that there was a good chance that Calcium Hydroxide was used as an interappointment medicament within the canals…

The argument to this would be, “Well if the root canal had been done properly, you could have finished it in one appointment, without the use of Calcium Hydroxide, and still have had the same results.” Maybe, but you’d be hard-pressed to support this by literature. The rebutt then becomes, “Well they use a different technique that’s not as good as mine.” Again, it’s difficult to make a case that lateral condensation is better than vertical condensation, or that apical canal enlargement (done properly) lowers the prognosis from minimal apical canal instrumentation techniques.

That’s something that should make many of us go, “Hmm.”

1. Trope M, Delano EO, Orstavik D. Endodontic treatment of teeth with apical periodontitis: single vs. multivisit treatment. J Endod. 1999 May;25(5):345-50.
2. Nair PN, Sjogren U, Figdor D, sundqvist G. Persistent periapical radiolucencies of root-filled human teeth, failed endodontic treatments, and periapical scars. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999 May;87(5):617-27.