Comparative evaluation of two digital technologies for dental radiographs: CCD-sensor (Sidexis®) versus sensor plate (Digora®)

Objectives: Two systems with different technologies for intraoral digital radiographs were evaluated in vitro and in vivo and compared to conventional dental X-rays. Material and Methods: Spatial resolution was determined for all three systems. Picture noise and distortion effects of both digital systems were evaluated. The permanence of the stored information content was examined for the sensor plate (= storage phosphor). Additionally, rectangular bone blocks with inserted implants and artificial bone defects were exposed with all systems and the images were quantitatively evaluated. 79 digital radiographs of 51 patients served for the examination of the diagnostic relevance of the images in comparison to conventional dental X-rays of the same patients. All data were processed with professional statistical software (SAS for Windows, Release 6.12). Results: Conventional film exhibited the best spatial resolution (20Lp/mm) followed by the CCD-sensor (11Lp/mm) and the sensor plate (8Lp/mm). Storage phosphor offered a wide dynamic range, but the information content underwent a distinctive increase in noise within 12 hours post exposure. Measurements of the defined bone defects were most precise with the CCD-system for both vertical and horizontal dimensions. On the other hand the CCD-sensor presented a considerably high image noise. Another drawback of the CCD-sensor was the rather complicate in vivo application compared to both conventional films and sensor plates. Conclusions: Though the compared systems exhibited distinctive differences in the spatial resolution, this parameter had less impact on the quality of the images than picture noise and contrast. Both digital systems are considered to be appropriate for diagnostic purposes. However, comparing the two digital systems, the storage phosphor seems to be favorable for its easier handling, radiation reduction, and better imaging quality. Schlagwörter: digital dental radiography, CCD sensor, storage phosphor, dose reduction