Estimation of Clinical Axial Extension of Class II Caries Lesions with Ultraspeed and Digital Radiographs: An In-vivo Study

This study compared the newly introduced direct digital radiographic (DDR) system (RVG-6000) with conventional bitewing radiographs (D-speed film) to estimate the extension of Class H caries lesions. The patient's discomfort related to placement of each radiographic packet was also evaluated. Fifty-one Class H caries lesions were selected. Affected teeth were radiographed with D-speed film and the RVG-6000 size 2 sensor. Patients were asked to complete a one-page questionnaire regarding discomfort during the radiographic examination. The true caries depth was validated clinically from intra.-operative photographs that captured the cross-sectional views of the lesion at its deepest point. During the operative procedures, the cavitation status was also recorded. A reference device was placed on the occlusal surface of the treatment or the adjacent tooth before taking radiographs and during the operative procedure. The caries lesion extension from the dentino-enamel junction (DEJ) was measured in mm on each radiograph and the results were compared to the true clinical depth. Both radiographs significantly underestimated the clinical depth (p<0.0001), but the RVG-6000 images were significantly closer to the actual depth of the lesion than the D-speed film (p=0.0031). All of the lesions which were diagnosed radiographically to be deeper than I nun into dentin were cavitated. Size, sharp edges of the sensor or both comprised the source(s) of most of the discomfort caused by D-speed film (64%) and RVG-6000 sensor (79%). The results of this study showed that both types of radiographic images tend to underestimate caries depth; however, the RVG-6000 image was more accurate than the D-speed film. This study also provides information about sources of the patient's discomfort associated with these radiographs.