Das ICDAS-II-System der Kariesdiagnose : Eine In-vitro-Studie zur Korrelation von Histologie und Röntgenaufnahmen bei Anwendung digitaler Medien

Modern cariology demands a reliable occlusal caries detection. Through large-scale studies with multiple participating study centers new classification systems, like the International Caries Detection and Assessment System II (ICDAS-II), can be vaildated. Due to the distance of the participating centers the ICDAS-II must be validated with regard to the application of digital media. Therefore, this study investigates the reproducibility of caries detection on occlusal surfaces on radiographs and digitised histological tooth sections in comparison to their originals. Material and methods: 100 extracted human teeth were visually scored (ICDAS-II) at 181 investigation sites by a consensus group (Jablonski- Momeni et al., 2008a). Subsequently conventional and digital radiographs of these teeth were taken. The analogue radiographs were digitised by photographing them with a digital camera. All radiographs were scored according to the Ekstrand et al. (1997) classification. Afterwards the teeth were cut in sections and macro photographs of these sections were taken. The sections were scored on a macroscope and the digital images on a computer screen. The presence and extent of caries was scored according to two histological classification systems (Downer, 1975; Ekstrand et al., 1997). All objects in this study were evaluated by two examiners. The reproducibility was measured by calculating the Cohen's kappa. The effect size was determined using Cohen's d. The correlations were expressed by the Spearman correlation coefficient rs. The results of the different diagnostic systems were contrasted with the visual results in contingency tables. Results: The intra-examiner reproducibility for both histological classification systems and both examination techniques was substantial to almost perfect (weighted kappa = 0,615-0,882). Besides, the inter-examiner reproducibility ranged from moderate to substantial (weighted kappa = 0,529-0,681). Comparing the kappa values between viewing the sections under the macroscope and viewing the digital images no effect or only a small effect between both examination techniques could be observed (effect size 0,05-0,48). The Spearman correlation coefficient revealed high agreement between both classification systems for both examination modalities (rs = 0,742-0,964). The ICDAS-II showed moderate performance when contrasted with histologic or radiographic examinations, with rs = 0,488-0,634 and rs = 0,449-0,593 respectively. The different radiographic methods showed moderate correlations when compared among each other (rs = 0,414-0,556). Conclusion: Digital images of tooth sections can be sent electronically to participating study centers without any impact on scoring quality. When evaluating radiographs the digitisation causes no changes in diagnostic results. Compared with histology the ICDAS-II can detect a high percentage of carious lesions at the enamel-dentine junction.