When the patient returned for the procedure, the dentist recorded an estimated working length of 20mm. However, after taking a periapical radiograph, he noted the three endodontic instruments were 4-5mm short of the radiographic apex and increased the working length to 22mm. The radiograph also showed periapical radiolucency characteristic of chronic infection around the mesial root.

During the procedure, an endodontic file broke and a 4mm section was retained in the mesio-buccal canal. The dentist did not record how the fracture happened, although he informed the patient and advised him that the tooth would need to be monitored over the long term. The dentist completed the procedure with the patient's consent.

Soon afterwards, the patient returned because the LL6 tooth had fractured and was causing him severe pain. This time, it was agreed that tooth could not be saved and it was agreed the dentist would make a referral for extraction because the tooth's curved roots made the procedure more complicated.

The extraction was carried out successfully 10 days later when it was discovered the broken endodontic file had penetrated 2mm through the apex of the mesio-buccal root.

The patient later made a claim against the dentist, alleging that the root canal treatment had been negligently carried out and that the dentist had missed earlier opportunities to diagnose and treat the tooth.

The DDU sought the opinion of an expert GDP witness who was critical of the dentist's treatment, believing it fell below an appropriate clinical standard. In particular, the expert was critical that a post-operative radiograph was not taken and of the dentist’s failure to clean, shape and obturate the root canal system.

With the member's agreement, the DDU offered to settle the claim and the claimant accepted £6,000 in compensation.

The endodontics files - broken instrument

The endodontics files - broken instrument