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Gutierrez, Cecilia (2008): DIFOTI (Digital Fiberoptic Transillumination): Validität In Vitro. Dissertation, LMU München: Medizinische Fakultät



This scientific work aims to determine the sensitivity and specificity of the DIFOTI system and to assess its diagnostic performance in detecting initial caries. Forty five sound teeth were randomly assigned to two groups. One group consisted of unaltered teeth (N=18). In the second group, an artificial carious lesion was created (Damato et al., 1988) on the buccal (N=9), proximal (N=9) and occlusal surface (N=9). To evaluate proximal caries, a proximal contact was simulated. Images of teeth were taken with DIFOTI. In addition to the DIFOTI standard software, the images were analyzed with View3D, a special software, performing an evaluation comparable to the one described by De Josselin de Jong et al., 1995 to quantify light scattering. The specimens were then sectioned, revealed an average depth of 62.39µm of the carious lesions and used as gold standard for the subsequent evaluation. Based on visual observation of the digitized images, sensitivity and specificity values were: 1.00 and 0.88 for smooth surfaces, 0.82 and 1 for occlusal surfaces, and 0.44 and 0.83 for approximal surfaces, respectively. Calculation of area under the ROC curve utilizing light penetration measurements of the device revealed values 0.69 corresponding to the 1% quantile gray level of DIFOTI image, and 0.59 for the median. DIFOTI has shown excellent sensitivity and specificity for buccal and occlusal superficial artificial lesions. However, it has poor ability to detect incipient proximal caries. Nevertheless, it still has good specificity proximally. With the currently used software, View3D, the gray-value evaluation fails to serve as an objective measure for caries diagnosis and requires further investigation.