Evidence Checklist for Alleged Endodontic Negligence: Identifying Missed Canals

In dental medico-legal practice, claims involving endodontic failure frequently focus on the identification of missed canal anatomy. When a tooth fails to resolve following root canal treatment, or presents with persistent apical periodontitis, instructing solicitors must determine whether the outcome resulted from a failure to meet the appropriate standard of care in identifying and instrumenting the full root canal system. A methodical approach to the evidence, grounded in objective radiographic and clinical documentation, is essential for a robust expert report.

Clinical Documentation and the Records Review

The foundation of any expert analysis under CPR Part 35 lies in the completeness of the clinical records. When assessing a claim for missed canals, the following documentation is typically required:

• Pre-operative radiographs: These provide evidence of apical health and the root and canal morphology prior to treatment.
• Working length radiographs and master cone films: These are used to evaluate the clinician’s ability to locate canal orifices and achieve working length.
• Post-operative radiographs: These allow for an assessment of the obturation quality and the presence of any unfilled canal spaces.
• Comprehensive contemporaneous clinical notes: The notes should reflect the clinician’s diagnostic process and exploration of the pulp chamber anatomy.

The expert witness examines these records to establish whether the failure to identify an additional canal constituted a breach of duty. Certain teeth, such as upper molars, possess complex internal anatomies, and the clinical records should reflect the decision-making process concerning this complexity.

Radiographic Assessment and Diagnostic Criteria

Radiographic evidence is a primary tool in endodontic claims. Experts must distinguish between an adverse clinical outcome and a breach of duty; a persistent apical lesion does not automatically imply that the treatment was performed negligently. The expert determines whether a missed canal was visible on available imaging or whether the pre-operative status suggested an anatomical complexity that warranted specific clinical interventions.

When reviewing imaging, the expert considers:

• Canal identification: Whether the floor of the pulp chamber was adequately explored.
• Obturation density: Whether the obturation suggests a void in a potential canal system.
• Radiographic interpretation: Whether the information available to the clinician at the time supported a different treatment pathway.

Experts should avoid the risks of hindsight bias, focusing instead on the evidence available to the treating clinician at the time of the procedure.

Addressing Breach and Causation

The expert report must address breach of duty and causation as distinct components. In cases of endodontic failure, this involves considering whether, but for the failure to identify the missed canal, the tooth would likely have been successfully retained. Where pre-existing periodontal disease or structural loss is present, causation may be contested. The report should evaluate the extent to which the endodontic failure, compared to other clinical factors, contributed to the loss of the tooth or the necessity for further intervention.

The Role of the Expert Witness

Selecting an expert with clinical experience in contemporary root canal therapy is vital. The expert’s role under CPR 35.3 is to provide an opinion on the standard of care as it existed at the time of treatment, referencing established dental principles. Under CPR 35.10, the report must contain the substance of the expert’s instructions. While CPR 35.7 allows for the appointment of a single joint expert in appropriate circumstances, CPR 35.12 provides for discussions between experts to narrow issues in dispute; a single joint expert does not participate in a joint statement process with a second expert.

Practical Considerations for Solicitors

To assist in the preparation of a report, solicitors should obtain all relevant diagnostic records, including any CBCT scans. Providing a clear chronological history enables the expert to contextualise the findings. Questions posed to the expert under CPR 35.6 should be proportionate and focused on the specific allegations of failure. For further context, solicitors may review practical examples of checklists for complex reports. By focusing on objective evidence, solicitors can ensure the expert is well-positioned to assist the court in resolving the dispute.