Accuracy of direct digital radiography for detecting occlusal caries in primary teeth compared with conventional radiography and visual inspection: an in vitro study

Abstract

Objectives: the diagnosis of caries lesions is still a matter of concern in dentistry. The diagnosis of dental caries by digital radiography has a number of advantages over conventional radiography; however, this method has not been explored fully in the field of paediatric dentistry. This in vitro research evaluated the accuracy of direct digital radiography compared with visual inspection and conventional radiography in the diagnosis of occlusal caries lesions in primary molars.

Methods: 50 molars were selected and evaluated under standardized conditions by 2 previously calibrated examiners according to 3 diagnostic methods (visual inspection, conventional radiography and direct digital radiography). Direct digital radiographs were obtained with the Dixi3 system (Planmeca, Helsinki, Finland) and the conventional radiographs with InSight film (Kodak Eastman Co., Rochester, NY). The images were scored and a reference standard was obtained histologically. The interexaminer reliability was calculated using Cohen's kappa test and the specificity, sensitivity and accuracy of the methods were calculated.

Results: examiner reliability was good. For lesions limited to the enamel, visual inspection showed significantly higher sensitivity and accuracy than both radiographic methods, but no significant difference was found in specificity. For teeth with dentinal caries, no significant differences were found for any parameter when comparing visual and radiographic evaluation.

Conclusions: although less accurate than the visual method for detecting caries lesions confined to the enamel, the direct digital radiographic method is as effective as conventional radiographic examination and visual inspection of primary teeth with occlusal caries when the dentine is involved.

Figure 1

Photograph of occlusal surface of a primary tooth. The black mark indicates the site for further analysis for conventional and digital radiography

Figure 2

Device designed especially for maintaining the source-to-image receptor distance

Figure 3

Example of a conventional radiograph of a primary tooth. This is the radiograph of the tooth in Figure 1

Figure 4

Digital radiograph of a primary tooth. This is the radiograph of the tooth in Figure 1

Figure 5

Example of the histological section of the primary tooth. This is a section of the tooth in Figure 1. The double arrow indicates the extension of the lesion inside the enamel (D2)