A relatively new patient visited their practice complaining of a painful LL5. On examination, the dentist noted the tooth was tender to percussion and recommended root canal treatment.

With the patient's consent, the dentist carried out the procedure which involved filing the tooth to a length of 21mm with a size 30 endodontic file and then filling the canal with a size 30 gutta percha point. Radiographs taken at the time did not extend to the apex, but show a very poorly condensed root filling. The dentist continued to see the patient over the following nine years.

Twelve years after the root canal treatment, the patient complained to his new dentist of tenderness in the LL5. The dentist took a radiograph and prescribed antibiotics.

Three years after this appointment, the patient saw a third dentist, complaining of pain in the lower left quadrant. On this occasion, the dentist noted an obvious radiolucent area around the root of the LL5 and prescribed antibiotics. However, no treatment was provided and it was not until the patient visited an orthodontist, 18 years after the initial root canal treatment, that he was referred to an endodontist.

The specialist successfully carried out re-root canal treatment on the LL5 and gave the tooth a good prognosis.

Shortly afterwards, the patient brought a claim for negligence against the first dentist, seeking £1,750 in compensation and legal costs of £6,000. The letter of claim alleged that the dentist had not shown reasonable care and skill in the technical execution of root canal treatment. In particular, he had failed to establish an appropriate working length; clean, shape and obturate the root canal system; analyse the post-operative radiograph; and remedy the defects or refer the patient to a specialist. It was alleged that this had caused the patient to suffer irreversible pulpal pathology at LL5 and repeated episodes of pain and infection, as well as the avoidable need to crown the tooth.

To bring a successful claim, the claimant had to show that the dentist's treatment was negligent according to the standards of a reasonable dental practitioner at the time, and that the patient suffered harm as a result (causation).

The DDU argued that the dentist was not liable for the need to re-root treat the tooth or crown it because the tooth had remained symptom-free for over 12 years. It was always likely that a tooth that had been root-filled so long ago would eventually require further treatment, but the fact that the re-rooted tooth had been restored and now had a good prognosis was clearly an excellent result for the patient.

However, it was accepted that the dentist did fall short of the established standards at the time by failing to take radiographs which displayed an accurate working length, and by not filling the canals adequately and that this was the cause of repeated episodes of pain and infection. The DDU eventually settled the claim for the smaller sum of £1,000 in compensation and £3,000 in legal costs.