A videobased computer assisted densitometric image analysis (CADIA) system to quantify alveolar bone density changes on standardized dental radiographs was tested. An algorithm was used for grey level correction of a subsequent image to the baseline image. Quantitative information regarding positive and/or negative grey level changes were obtained automatically. Comparison of the ability of CADIA to detect surgically induced bone loss with interpretation of digital subtraction images and conventional radiographic interpretation revealed that CADIA was the most sensitive of the 3 methods, followed by interpretation of digital subtraction images which was considerably more sensitive than conventional radiographic interpretation. CADIA was capable of assessing differences in alveolar bone changes due to periodontal surgery between sites exposed to ostectomy/osteoplasty and control sites and sites exposed to periodontal surgery without ostectomy/osteoplasty. Finally, CADIA was capable of assessing differences in remodeling activity over 4-6 weeks after periodontal surgery between 45 surgical sites and 45 control sites. The system offers an objective method to quantitatively follow alveolar bone density changes over time and appears to be the most sensitive of previously described radiographic interpretation techniques.

The purposes of this study were to evaluate digitized images from standardized radiographs for quantitative changes in alveolar bone density following periodontal surgical procedures, and to correlate these changes to the changes in the clinical parameters P1I, GI, PD, AL. 14 crown-lengthening procedures for restorative purposes were performed in 13 patients and 15 modified Widman flaps were performed in 15 patients, providing 61 surgical interdental test sites and 61 matching controls. Standardized radiographs were obtained immediately post-operatively, and at 1 and 6 months postsurgically. Digitized images were obtained from the radiographs by means of a video camera linked to an image processor and a computer. Quantitative information regarding density changes within windows covering the interdental alveolar crest was obtained after superimposition and grey-level correction of images to be compared. The results indicated statistically significantly more density loss 4 to 6 weeks postsurgically at test sites treated by periodontal surgical procedures compared to corresponding controls. Significant differences in the remodelling activity between the patients exposed to crown lengthening procedures for restorative purposes and the periodontitis patients in the period 1 to 6 months postsurgically were evident. CADIA assessed differences in the tissue changes in the healing phase following periodontal surgical procedures, which were not detected by the clinical variables applied.

This study attempted to evaluate quantitative changes in radiographic density as an indicator of progression of periodontitis. Twenty-one subjects with a history of periodontitis were monitored at baseline, 3, 6, and 9 months using duplicate probing attachment level (PAL) measurements from stents and computer assisted densitometric image analysis (CADIA) of standardized radiographs. Results indicate that the majority of sites exhibited no PAL change during the 9-month period; however, the percentage of sites with loss increased with time. A mean of 6.1% of the sites/patient exhibited probing attachment loss during the study, as compared to a mean of 38.3% of the sites/patient that exhibited a loss of radiographic density. Due to the two dimensional nature of radiographs, density analysis was calculated in terms of radiographic "complexes" of multiple probing sites. There was significantly more density loss at complexes with greater than or equal to 2 mm of attachment loss than at sites with no change in PAL at 9 months; there was no such difference noted at 3 and 6 months. Also, density loss tended to increase as more sites within each complex experienced PAL. Although there was a significant correlation between mean density and PAL changes during the same time interval, there were wide variations at individual sites. This study suggests that there is a complex relationship between density change on radiographs and PAL change. The difficulties inherent in comparing highly sensitive new technologies to relatively imprecise clinical measurements of the attachment level are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)

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.