Image quality of digital and film radiographs in applications sent to the Dental Insurance Office in Sweden for treatment approval.

In July 2002, a new dental insurance program was introduced in Sweden. For all patients over 65 years, prior approval for all prosthetic work would need to be obtained from the Dental Insurance Office. From October to December 2002, 540 cases were randomly selected for evaluation from the 14,624 applications that had been sent from throughout Sweden to the Dental Insurance Office in Lund. Our aims were to appraise the quality of the radiographic examinations and to compare the quality of the digital with the film (X-ray film) radiographs. The radiographic examinations were evaluated as a whole in relation to the proposed treatment and in detail using specific criteria such as density, contrast, unsharpness, angulation, and receptor position error. The quality variables were evaluated as acceptable or unacceptable. A total of 4,687 intra-oral and 206 panoramic radiographs were evaluated. Thirteen per cent of the intra-oral radiographs and 9% of the panoramic radiographs were taken with a digital technique. Most of the digital radiographs--7o% of the intra-oral and 61% of the panoramic radiographs--were submitted on microdisk. Twenty-eight per cent of the intra-oral digital radiographs, however, were submitted on paper. The radiographic quality in 15o cases (28%) were found to be unacceptable for assessment of the proposed treatment. The most common error--both in digital and X-ray film radiographs--was in receptor position. Significantly more errors were found in the intraoral digital radiographs compared to the radiographs taken with X-ray film. Most of the errors in the digital radiographs were detected in the paper copies. In conclusion, it is possible to improve the radiographic quality in applications for treatment approval, and the dentists had more difficulties with the digital technique than with X-ray film.