Above: CBCT Scan slices UL6 a) sagittal view b) coronal view c) axial view
One of the most common challenges in Endodontics is resorption. And when this radiolucency appears in the radiograph… a few questions are raised. Which could be the reason for the resorption? Is it internal or external? What is the real size of the resorptive defect? If it is external, does it communicate with the pulp? And if it is internal, has it perforated the root surfaces?
All these questions are difficult to be answered just by looking at the standard periapical radiographs. Having been exposed to the “in-house” fascinating CBCT world for the last two years, I feel privileged and can say with certainty that CBCT is mandatory in cases of resorption. Being able to visualize the tooth and its surrounding tissues in three dimensions can give an answer to these questions, assist in accurate diagnosis and facilitate correct treatment planning.
I saw an interesting resorption case recently. A 43 years old male was referred for possible treatment of his UL6 as he had been experiencing localised pain. The tooth was root treated about 9 years ago by a previous dentist who managed to treat four canals (including the MB2!). The patient reported occasional mild discomfort over the years in the area of the UL6. About 1 month prior to our consultation, he experienced localised pain and an associated swelling.
Pre-operative radiograph UL6
Post-operative radiograph UL6
Radiographic examination showed that the UL6 had a radiographically optimal root canal treatment with four canals being root filled and the root fillings extending almost to the full length of the roots. There was a periapical radiolucency at the MB root apex. The radiograph also showed a circular radiolucency at mid-apical root level of the MB root, indicating presence of resorption. We can all agree that detecting the resorptive defect was easy. But… how could I be certain whether this is an internal or an external resorption? It looked internal as it was centered in the root… but even in that case, I could never be sure whether it has perforated the root walls. Whether an orthograde approach would be safe and sufficient or it had to be combined with a surgery.
Exposing the CBCT scan in this case, gave me the opportunity to visualize the resorptive defect in three dimensions. The scan showed that the resorptive defect was internal, involving both the MB and MB2 canals, and that it had not perforated the root walls.
Working alongside the scan throughout treatment, made the treatment easier, more interesting and less stressful. I was able to safely irrigate and activate my irrigants inside the resorptive defect without the fear of extrusion. And when it came to the obturation, a thermoplasticised root filling technique was followed to assure the resorptive defect is 3-dimensionally sealed.
So, why guessing the answer in all these questions when we have the real answer in front of us? The benefits of taking the CBCT scan in resorption cases overweight the risks. The ultimate aim is to save patient’s teeth and therefore, where possible, nothing is more important than being able to provide an accurate diagnosis and a more predictable treatment plan!
I am planning to review this tooth in 6-9 months time, hopefully I can see some healing at that time… perhaps another blog.