[Digital subtraction radiography technique in oral diagnosis]. / E technike tes psephiakes aphairetikes aktinographias ste diagnostike tou stomatos.

The introduction of digital subtraction radiography for the evaluation of standardised dental radiographs offered increased diagnostic accuracy in the detection of subtle density changes over interpretation of conventional radiographs. The digital imaging techniques for the analysis of dental radiographs were reviewed with emphasis on periodontal diagnosis. Recently, these methods, which have been extensively tested in vitro, were applied to clinical trials for the assessment of alveolar bone density changes due to progression of disease or healing following therapy.

Computer-assisted densitometric image analysis (CADIA) for the assessment of alveolar bone density changes in furcations.

The purpose of this study was to test the applicability of computer-assisted densitometric image analysis (CADIA) for the quantitative assessment of alveolar bone density changes in furcations of multirooted teeth. In 21 patients, standardized radiographs were obtained immediately after and at 1, 6 and 12 months after periodontal flap procedures. Digitized images were obtained by means of a video-camera combined with an image processor that was linked to a computer. Quantitative information regarding density changes within windows covering furcation areas was obtained after superimposition and grey-level correction of images to be compared. 1 month after flap reflection, significantly more density loss was obtained in test furcations exposed to periodontal surgery, compared to the density changes in control furcation exposed to scaling and root planing. At 12 months, however, significantly greater increase in density was measured in test furcations compared to the 1-month results. The radiographic data were compared to the clinical parameters. In test furcations, there was a negative correlation of r = -0.52 between the GI and the loss in density at 1 month, and a negative correlation of r = -0.61 between the loss in density at 6 months and the probing attachment level at 12 months. These results indicate that CADIA may give valuable additional diagnostic information regarding alveolar bone density changes in furcations in studies on periodontal therapy.