Development of quality measurement instruments for root canal treatment

To devise measurement instruments for 'quality' of root canal treatment to assess training and outcome of general dental practitioners working within primary care settings.

Scoring systems relating to quality of root canal treatment were developed using expert consensus and published literature. Domains scored included the Treatment Process, Quality of the Obturation, Clinical Healing, Radiographic Healing and Tooth Complexity. Scoring systems were applied to 10 clinical cases treated by each dentist at the beginning and 10 cases treated at the end of their clinical training and 135 cases treated after completion of training. The dentists recorded the treatment process and clinical healing in clinical logs. Two examiners independently scored the radiographs after undertaking calibration and training. Inter- and intra-examiner reliability of scoring radiographic outcomes was tested using Cohen's Kappa statistics.

An instrument was created with four domains to assess quality (two for process and two for outcome of root canal treatment), and a measure of case complexity. Domains of treatment process (n = 240 teeth), outcome (n = 32 teeth) and complexity (n = 215 teeth) were scored using radiographs. The Kappa scores for intra-examiner reliability between 0.22 and 1, whilst inter-examiner reliability ranged between 0.18 and 0.99.

Evidence-based scores for assessment of the quality (process and outcome) and complexity (structure) of root canal treatment were devised. They were reliable, provided that clinicians were trained in record keeping and examiners have in depth training and calibration in the use of the instruments.