Effect of different diagnostic thresholds on dental caries calibration - a 12 month evaluation

Objective: To analyze the reproducibility of a calibration trial, at different diagnostic thresholds of dental caries, in a 12-month evaluation. Methods: A group of dental examiners (n=11), who had previous experience in epidemiological surveys, participated in the study. An initial training phase (theoretical and clinical) and five calibration exercises (baseline, 3, 6, 9 and 12 months) were arranged. World Health Organization (WHO) criteria, including the active initial lesions (IL) were used. Six- to 7-year-old children took part in the study. They were selected according to past history and dental caries activity. The data were analyzed at WHO and WHO+IL diagnostic thresholds in accordance with tooth and dental surfaces. Results: Excellent mean intra- and inter-examiner Kappa values were obtained for both diagnostic thresholds, in accordance with tooth and surface, during the calibration phases. However, the most relevant errors were related to the decayed component and to IL diagnosis. Conclusion: It was possible to use the methodology proposed in this study in epidemiological surveys when examining the mixed dentition, although new strategies to improve training in IL diagnosis and calibration are necessary.