The present experiment was undertaken to test the hypothesis that new connective tissue attachment may form on a previously periodontitis involved root surface provided cells originating from the periodontal ligament are enabled to repopulate the root surface during healing. A mandibular incisor with advanced periodontal disease of long standing (the distance between the cemento-enamel junction and the alveolar bone crest was 9 mm) was subjected to periodontal surgery using a technique which during healing prevented the dentogingival epithelium and the gingival connective tissue from reaching contact with the curetted root surface. Preference was hereby given to the periodontal ligament cells to repopulate the previously diseased root surface. After 3 months of healing a block biopsy containing the incisor and surrounding tissue was sampled. The histological analysis revealed that new cementum with inserting principal fibers had formed on the previously diseased root surface. This new attachment extended in coronal direction to a level 5 mm coronal to the alveolar bone crest. This finding suggests that new attachment can be achieved by cells originating from the periodontal ligament and demonstrates that the concept that the periodontitis affected root surface is a major preventive factor for new attachment is invalid.

The present investigation was performed to study the frequency of recurrence of periodontitis in diabetic subjects, who, prior to the initiation of a 5-year period of monitoring, were treated for moderate to advanced periodontal disease. 20 patients with diabetes, type 1 (IDDM) or type 2 (NIDDM) and 20, sex and age matched, controls with similar amounts of periodontal tissue destruction, were selected for the study. Following a screening examination, all patients were subjected to non-surgical periodontal therapy (oral hygiene instruction, supra- and subgingival scaling). 3 months later, the baseline examination for the study was performed. This included assessments of several parameters such as: number of teeth, plaque, gingivitis, probing pocket depth and probing attachment level. 6 months after the baseline examination, all 40 subjects were recalled for a 2nd examination. Sites which at this 6-month examination exhibited bleeding on probing, and had probing depth > 5 mm, were scheduled for additional surgical therapy (modified Widman flap). Following this selective additional therapy, the main period of monitoring was initiated. During this period, a plaque control program was repeated every 3 months. Re-examinations regarding plaque, gingivitis, probing depth and probing attachment level were performed 12, 24 and 60 months after the baseline examination. The findings from the examinations disclosed that diabetics and non-diabetics alike, treated for moderately to advanced forms of adult periodontitis, during a subsequent 5-year period, were able to maintain healthy periodontal conditions. Thus, the frequency of sites which exhibited signs of recurrent disease was similar in the 2 study groups.

The aim of the present trial was to study the effect of meticulous supragingival plaque control on (i) the subgingival microbiota, and (ii) the rate of progression of attachment loss in subjects with advanced periodontal disease. An intra-individual group of sites exposed to non-surgical periodontal therapy served as controls. 12 patients with advanced periodontal disease were subjected to a baseline examination (BL) including assessments of oral hygiene status, gingival condition (BoP), probing depth, clinical attachment level and subgingival microbiota from pooled samples from each quadrant. The assessments were repeated after 12, 24 and 36 months. Following BL, a split mouth study was initiated. The patients received oral hygiene instruction, supragingival scaling and case presentation. 2 quadrants in each patient were identified as "test" and the remaining 2 as "control" quadrants. Subgingival therapy was performed in all bleeding sites in the control quadrants. Oral hygiene instructions and plaque control exercises were repeated once every 2 weeks during the initial 3 months of the study. Thereafter the plaque control program was repeated once every 3 months for the duration of the 3 years. Sites demonstrating loss of clinical attachment > or =2 mm in the test quadrants were treated subgingivally. The results showed that in both test and control quadrants repeated oral hygiene instructions and supragingival plaque removal procedures resulted in low plaque scores throughout the study. The gingival bleeding scores and the frequency of periodontal pockets > or =4 mm was, however, significantly higher in the test quadrants than in the control quadrants. At the end of the 3 year study, the control quadrants showed significantly more reduced (> or =2 mm) pockets than the test quadrants, 265 versus 96. The number of sites in the test quadrants showing probing attachment loss > or =2 mm was more than 4x greater than in the control quadrants (59 versus 13). The microbiological findings indicate a more pronounced reduction only for P. gingivalis in the control quadrants. None of the other 4 marker bacteria consistently reflected or predicted the clinical parameters. The present study shows that only supragingival plaque control fails to prevent further periodontal tissue destruction in subjects with advanced periodontal disease.

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.

In the present study, the frequency of sites exhibiting gingival inflammation and periodontal tissue breakdown was assessed in one group of 46 individuals (19-25 years old; test group T) who had suffered from diabetes mellitus (Type 1) for 10 years or more, and in another group of 41 non-diabetic controls (18-26 years old; control group C). Each individual was examined regarding oral hygiene status, gingival conditions, probing depths, probing attachment levels and gingival recessions. The interproximal marginal bone level was assessed in bitewing radiographs. No significant differences were found between the 2 groups regarding their oral hygiene status, frequency of sites with probing depths of greater than 3 mm and the position of the interproximal alveolar bone margin. The mean distance between the cemento-enamel junction (CEJ) and the interproximal bone crest was in group T, 0.91 +/- 0.14 (SD) mm and in group C, 0.95 +/- 0.18 (SD) mm. About 80% of the individuals in both groups were free from signs of marginal bone loss and only 1 subject in each group had greater than 6 sites with definitive bone loss. The group of diabetic patients had higher frequencies of inflamed buccal/lingual gingival units, gingival recessions and sites with attachment loss of greater than or equal to 2 mm. Most of the sites (85%) with attachment loss were located at the buccal and lingual surfaces. There were no significant correlations between the periodontal variables and the duration of diabetes, insulin dosage and HbA1 level. Individuals with both retinopathy and nephropathy had significantly more gingival inflammation than diabetic individuals without complications.