A common complication in Endodontics is perforation. And when things want to go wrong, they will inevitably go wrong… but hey, perforation is not the end of the path for many teeth if managed properly.
I have waited to post this article until I reviewed a recent perforation case I retreated last year. The patient (A 58 year old female) was referred by her general dentist regarding possible retreatment of her LR7. Her only complaint was a ‘lump’ near the LR7.
Clinically, the LR7 was restored with a precious metal crown with adequate margins. A suppurating sinus was identified on the buccal alveolar mucosa adjacent to the LR7. Probing depths were within normal limits. The periapical radiograph showed three filled root canals in the LR7 with a periapical radiolucency.
The cone beam CT scan confirmed a periapical radiolucency beneath the root filled LR7, with obturation material in the mesiobuccal and distal canals, an untreated mesiolingual canal. The third ‘filled canal’ was actually gutta-percha placed through a perforation into the furcation, positioned lingual and distal to the mesiobuccal canal. Luckily there was no obvious pathology at the perforation site (see scan slices – Figs 3 & 4).
Fig.1 Pre-operative radiograph LR7
Fig. 2 Pre-operative image LR7 (sent by referring dentist)
Fig.3 CBCT scan slices LR7 a) Sagittal view b) Coronal view mesial root c) Coronal view distal root
The reason for the radiolucency was contamination from an untreated canal and probable recontamination in the other canals. It seemed that the perforation itself was not contributing to the apical pathology.
Treatment was carried out over two appointments. The important untreated mesiolingual canal was identified, patency was achieved in all the root canals and they were fully chemo-mechanically debrided. An attempt was made to remove the extruded GP but rather predictably it broke on getting hold of it. I therefore sealed the perforation with MTA. Calcium hydroxide with iodoform was used as intra-canal medication.
At the subsequent appointment the patient reported that the tooth was asymptomatic and the buccal sinus had healed. The LR7 was obturated and permanently sealed and restored with an amalgam Nayyar core restoration through the existing crown.
The patient was reviewed six months later. Happily she reported that the LR7 had remained asymptomatic since treatment was completed and the buccal swelling had long gone.
Fig.4 CBCT scan slices LR7 - axial view at different levels
Radiographic examination showed complete resolution of the periapical radiolucency associated with the LR7, indicating the outcome of the endodontic treatment to be successful with complete healing.
It feels that the dentist who carried out the primary treatment did not realised that he/she was working outside the root as he/she even obturated the ‘prepared’ canal, well… these things happen. Sight of blood throughout the procedure and unstable apex locator readings could have hinted that things might not were quite well.
Fig. 5 Perforation repaired with MTA
In my opinion, accurate diagnosis and treatment plan was key to save this tooth.
Prognosis of perforated teeth mostly depends on elimination and prevention of infection of the perforation site. In addition, the use of a biocompatible material that seals the perforation will limit periodontal inflammation.
Fig 6 Final radiograph obturation LR7 Fig. 7 Review radiograph LR7
In this case the perforation was fortunately not yet contaminated which was an important diagnostic step in treatment planning and assessing prognosis at an early stage. The pre-operative radiograph sent by the referring dentist did not show any evidence of perforation/extruded material related to the mesial root. We probably would have picked up this using a periapical radiograph with different angulation, we certainly would have found this on starting treatment, but the complex nuances of what was happening inside this tooth at this early stage would have been entirely guesswork, leaving a questionable prognosis and the possibility that another implant might be the favoured more predictable option.
The CBCT scan gave us full certainty that there was no osseous destruction or pathosis related to the extruded material. From there, we knew that we could give a second chance to this tooth, as we successfully did. At the Academy of Advanced Endodontics, we have the opportunity to use the on-site Cone Beam CT Scanner as part of the examination. This enhances our ability to observe what is inside the tooth, and any associated disease. Diagnosis will be more accurate facilitating enhanced treatment planning with a more predictable prognosis and the ability to target treatment where it is necessary. This can lead to quicker and easier treatment, often reducing the overall costs of treatment, and what really matters… saving patient’s teeth!