Accuracy of diagnosing occlusal caries using enhanced digital images

Objectives: To compare the accuracy of detecting occlusal caries lesions on original images vs images digitally enhanced for sharpness, zoom and pseudocolour. Methods: Four hundred images of 100 extracted third molars were examined for the presence or absence of occlusal caries by four observers, using a 5-point confidence scale. The observers had no prior knowledge of the distribution of the caries. The definitive diagnosis of caries was based on a histological assessment after sectioning the teeth. The diagnostic accuracy for each imaging mode was expressed by the area of the receiver operating characteristic (ROC) curve. Differences between the areas under the ROC curves were assessed using an analysis of variance. Results: The original image had a mean ROC curve of 0.75 (95% confidence interval (CI) 0.65-0.85). The ROC curves for sharpness, zoom and pseudocolour were 0.73 (95% CI 0.63-0.83), 0.76 (95% CI 0.61-0.81) and 0.70 (95% CI 0.60-0.80), respectively. These differences were not statistically significant (P = 0.96). The Cohen's kappa indicated good agreement among observers. Conclusions: In this in vitro study, the three enhanced images used did not affect the detection of occlusal caries.