Dr Julius Babayemi of Omnipark Dental Centre in Rainham, Kent discusses the examination of an endodontic retreatment case, utilising the enhanced magnification of the Carl Zeiss OPMI Pico microscope.
A female patient presented, complaining of pain and swelling associated with a previously root-filled tooth that was treated 5 years earlier. The pain had increased over the course of some days and a swelling developed on the buccal mucosa. This swelling led to pus discharge 5 days before presentation.
On presentation, the patient had a heavily restored dentition with upper anterior crowns on the UR1, UR2, UL1 and UL2. Likewise, the right maxillary quadrant had a 3 unit fixed-fixed bridge that opposed a large disto-occlusal restoration on the LR4, and mesio-occluso–distal restorations on the LR5 and LR6. The maxillary canines were discoloured, the UL4, UL5, and LL6 had indirect restorations, whilst the UL6 and LL5 had large amalgam restorations.
Examination using the Carl Zeiss Opmi Pico microscope revealed that the UR5 was the middle abutment within the 3 unit fixed-fixed bridge. It had a buccal draining sinus. The buccal margins of the UR5 and UR6 had receded and there was evidence of recurring carious lesions on the palatal of the UR5. The UR5 and UR6 were buccally displaced, but not mobile.
Radiographs were taken and confirmed a fixed-fixed 3-unit bridge with the UR6 and UR 5 acting as the abutments and the UR4 as the pontic. The pulpal floor was heavily prepared and the canal obturated, with a single cone fitted gutta percha. The apex showed radiolucency of 3mm x 2mm in diameter. The bridge pontic was overlaying a symptom-free buried retained root from the UR4, and the UR3 and UR6 appeared sound with no pathology.
The long post-treatment time and recent symptoms suggested that this was a non-healing lesion. Most radiolucent lesions heal within 12 months, although some lesions may take up to 4 years to resolve. The size of the periapical radiolucency, together with the fact that the root canal treatment was done 5 years earlier, suggested that the infection had been present for a number of years.
1. Chronic apical periodontitis with suppuration
2. Coronal leakage of the UR5 bridge retainer
3. Buried retained root UR4
4. Generalised mild to moderate chronic gingivitis
1. Root canal retreatment over two visits
2. Section off UR5 and UR4 from the 3-unit bridge
3. Following retreatment of UR5, restore with post/core cantilever bridge and retain UR6 as a single crowned tooth
4. Dismantle bridge, extract UR5 and retained root UR4 and replace with dental implant retained crown
5. Leave alone
The patient was keen to save the tooth, and not prepared for extraction. Besides, the UR5 was a functioning tooth as part of the bridge abutment and dentition. Hence, we discussed the options of retreatment versus surgical endodontics. For example, surgical endodontics has the advantage that the bridge would be left intact and undisturbed.
In addition, surgical endodontics in close proximity of the periapical lesion to the floor of the maxillary sinus can affect the risk level. The preoperative radiograph showed the upper border of the periapical lesion to be within a few millimetres from the maxillary sinus floor.
The patient was warned that the prognosis of the treatment depended on complete removal of the root filling material, and identification and subsequent negotiation and irrigation of the canals to their working lengths. Again, on dismantling the bridge, extraction could have been necessary if the tooth was unrestorable.
In spite of the above, the patient was keen on retreatment. Because of the coronal leakage distal of the UR5, a decision was made to section off the bridge between the UR6 and UR5, rather than working through and repairing the existing restoration.
The treatment was completed over 2 visits, the gutta percha was removed and the 2 canals were located, prepared and irrigated. On the second visit the patient reported that the tooth was now symptom free, the temporary filling was removed and the canals were re-instrumented and obturation completed. Post-operative instructions were given to the patient and a third appointment was made for post/core two-unit bridge preparation a week later.
At the third visit, the buccal sinus had cleared, and the patient confirmed that that she has not noticed any bad breath or foul taste from the discharging sinus. At this stage the final restoration of a 2-unit bridge was fitted.
It is argued that post treatment chronic apical periodontitis is primarily associated with persisting infection of the root canal system. This might be due to the inadequate canal preparation and obturation by the previous dentist that resulted into the failure of the root treatment. Examples of inadequate canal preparation include inadequate access, missed canals, instrumentation errors and coronal leakage of the final restoration.
In this case the enhanced magnification and visualisation provided by the Opmi Pico microscope was vital in assessing whether the dentition was restorable or not. It allowed me to assess for any cracks or fissures in the tooth root that would have helped the diagnosis and prognosis, but which in this case were not present. Secondly, it also helped me to ensure that all of the old filling material had been removed, as I was able to clearly visualise the magnified area.
Endodontic treatment such as this relies on the practitioner’s ability to adequately view the minute details within the oral cavity and the success of this case were dependent on the complete removal of the root filling material. This would not have been possible without the use of the microscope.
Dr Babayemi will be holding a ‘back to basics’ endodontic course in his practice in Kent for local practitioners to attend and explore the enhanced possibilities of utilising the latest magnification equipment and techniques. If you are interested in attending, or would like to find out more, please contact Dr Babayemi at firstname.lastname@example.org