Effect of Scaling and Root Planing on Alveolar Bone as Measured by Subtraction Radiography

Background: Scaling and root planing of diseased periodontal pockets is fundamental to the treatment of periodontal disease. Although various clinical parameters have been used to assess the efficacy of this therapy, radiographic analysis of changes in bone density following scaling and root planing has not been extensively researched. In this study, digital subtraction radiography was used to analyze changes that occurred in the periodontal hard tissues following scaling and root planing. Methods: Thirteen subjects with a total of 39 sites that presented with >3 mm of vertical bone loss were included in this study. Clinical examinations were performed and radiographs were taken prior to treatment and were repeated 6 months following scaling and root planing. Radiographic analysis was performed with computer‐assisted radiographic evaluation software. Three regions of interest (ROI) were defined as the most coronal, middle, and apical portions of each defect. A fourth ROI was used for each site as a control region and was placed at a distant, untreated area. Statistical analysis was carried out to evaluate changes in the mean gray level at the coronal, middle, and apical region of each treated defect. Results: Digital subtraction radiography revealed an increase in radiographic density in 101 of the 117 test regions (83.3%). A 256 gray level was used, and a value >128 was assumed to represent a density gain in the ROI. The average gray level increase was 18.65. Although the coronal, middle, and apical regions displayed increases in bone density throughout this study, the bone density of the apical ROI (gray level = 151.27 ± 20.62) increased significantly more than the bone density of the coronal ROI (gray level = 139.19 ± 21.78). A significant increase in bone density was seen in probing depths >5 mm compared to those <5 mm in depth. No significant difference was found with regard to bone‐density changes surrounding single‐ versus multiple‐rooted teeth. Conclusion: Scaling and root planing of diseased periodontal pockets can significantly increase radiographic alveolar bone density as demonstrated through the use of digital subtraction radiography.