Tuned aperture computed tomography and detection of recurrent caries

This study compared the diagnostic efficacy of four imaging modalities for the detection of artificially induced recurrent caries: intraoral film, direct digital bitewing images, tuned apertuce computed tomography (TACT) slices and iteratively restored TACT images using an in vitro model. Twenty-four posterior teeth were prepared for MOD inlay restorations. These were then restored with different restorative materials (amalgam, Herculite and Durafill). Lesions were simulated in half the number of surfaces studied. These lesions were created either at the intersection of the facial or lingual walls and the gingival floor or on the gingival floor midway between the facial and lingual walls in the proximal boxes of the MOD restorations. Analysis of observations from 8 observers using ROC curve reveal the superior diagnostic efficacy with TACT iteratively restored images (Az for TACT iteratively restored images = 0.9171, TACT slices = 0.7052, Film = 0.6608, direct digital images = 0.5979). ANOVA revealed significance with respect to the imaging modality used (p < 0.0001). The results suggest that TACT images hold promise as a more effective imaging modality than film or direct digital systems for detection of recurrent caries.