First Clinical Evaluation of the Duerr Vistascan Dental X-ray Image Plate Scanner

Methods: 10 clinical cases requiring repeated panoramic radiography were selected. One radiograph was taken with a conventional 250-speed film-screen combination (Agfa Dentus 1000 / Agfa regular) the other with the scanner system at identical exposure settings. The image zoom was adjusted to display every image pixel physically. 6 dentists answered a questionaire comparatively rating the image quality of several anatomical structures at a five point scale.

The image pairs were presented simultaneously in random order at a lightbox and a 17 inch monitor respectively. Preliminary results induced further manufacturers development. After Scanner replacement and software update 16 intraoral image pairs before and after endodontic treatment were taken, one with a conventional E-speed film (Agfa Dentus M2), the other with the storage phosphor. All intraoral radiographs were exposed at identical settings of 7 mA, 70 kV, 125 ms multipulse (Gendex oralix DC).

Results: Conventional radiographs were rated significantly better than the digital (mean 1.89 at a 5-point scale where 3 stands for equivalence, Standarddeviation 0.76). The clinical impact of the difference was rated moderately relevant (mean 2.91; SD 1.29). With intraoral images the difference was reduced (mean 2.55, SD 0.87) and both modalities acceptable for clinical practice.

Conclusions: Based on visual comparison the radiographic image quality of conventional films is superior to the scanner images exposed at identical settings. After technical revisement and focussing on intraoral films the difference was reduced. This might be due to technical improvements or to different comparative standards, because intensifying screens are used with conventional panoramic radiography but not with intraoral films. Further investigations are in process.

Funding: Clinical evaluation was sponsored by duerr corporation.