A total of 235 subgingival sites, including 104 progressive deep lesions from 61 untreated patients, 26 progressive deep lesions from 10 treated patients, 33 nonprogressive deep sites from 20 untreated patients, and 72 nonprogressive sites from 55 treated patients were examined for Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius. The periodontal disease progression was mainly determined on the basis of radiographic changes in the crestal alveolar bone level. A. actinomycetemcomitans isolation was carried out using the selective TSBV medium and B. gingivalis and B. intermedius isolations were performed using a nonselective blood agar medium. 1 or more of the 3 bacteria studied appeared in 99.2% of progressive periodontal lesions but only in 40.0% of nonprogressive sites. Culture-positive progressive periodontal sites in comparison with culture-positive nonprogressive sites showed higher median recovery rates of A. actinomycetemcomitans (0.5% vs 0.3%), B. gingivalis (30.5% vs 0.3%) and B. intermedius (4.9% vs 0.5%). Of total progressive lesions, 12.3% yielded solely A. actinomycetemcomitans, 21.5% demonstrated solely B. gingivalis, and 20.8% revealed solely B. intermedius. The A. actinomycetemcomitans--B. intermedius combination was found in 24.6% of progressive lesions. A. actinomycetemcomitans appeared in significantly higher prevalence in treated-progressive lesions (80.8%) than in nontreated-progressive lesions (42.3%). 32 of the 42 culture-positive nonprogressive sites yielded B. intermedius as the sole test organism. The main conclusion is that A. actinomycetemcomitans, B. gingivalis and B. intermedius are closely related to disease-active periodontitis, and more closely than to periodontal pocket depth. This finding is important in understanding periodontal disease etiology and pathogenesis and may also aid in a clinical setting to differentiate progressing and nonprogressing periodontal sites.

This study evaluated the statistical association of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius with progressive periodontitis. 146 adults with a history of advanced periodontitis contributed 105 "nonprogressing" and 130 "progressing" periodontal sites. Periodontal disease activity was assessed by radiographic changes in crestal alveolar bone level. The subgingival proportion of the 3 test bacteria was determined by selective and nonselective culturing. The relationship between bacterial proportions and disease progression was evaluated using subgrouping and multiple-regression analyses. All 3 test bacteria had to be considered in order to distinguish nonprogressing and progressing periodontitis with a reasonably high sensitivity. A recovery rate below 0.01% for A. actinomycetemcomitans, 0.1% for B. gingivalis and 2.5% for B. intermedius defined a site with nonprogressing disease with 87% sensitivity and 84% specificity. By utilizing transformed values of the bacterial recovery rates and optimal test criteria determined by multiple regression analysis, it was possible to obtain sensitivities between 83% and 95% and specificities between 86% and 69%. These 3 bacterial species might serve as valuable components of a periodontitis activity test based on microbiological variables.

The aim of the present clinical trial was to evaluate the effect of different modes of periodontal therapy on patients with moderately advanced periodontal disease and to express the findings in terms of probing pocket depth and attachment level alterations at periodontal sites with different initial probing depths. The material consisted of 16 patients, 35-65 years of age. Following a Baseline examination including assessments of oral hygiene status, gingival conditions, probing pocket depths and probing attachment levels, the patients were subjected to periodontal treatment. A "split-mouth" design approach of therapy was used and the jaw quadrants were randomly selected for the following different treatment procedures: (1) scaling and root planning, (2) scaling and root planing in conjunction with a gingivectomy procedure, (3) scaling and root planing in conjunction with an apically repositioned flap procedure without bone recontouring, (4) scaling and root planing in conjunction with an apically repositioned flap procedure including bone recontouring, (5) scaling and root planing in conjunction with a modified Widman flap procedure without bone recontouring and (6) scaling and root planing in conjunction with a modified Widman flap procedure including bone recontouring. The patients were following active treatment enrolled in a supervised maintenance care program including "professional tooth cleaning" once every 2 weeks during a 6-month period of healing, after which a final examination was performed. The investigation demonstrated that active therapy including meticulous subgingival debridement resulted in a low frequency of gingival sites which bled on probing, a high frequency of sites with shallow pockets (less than 4 mm) and the disappearance of pockets with a probing depth of greater than 6 mm. Between the Baseline examination and the 6-month re-examination, the probing attachment level for initially shallow pockets remained basically unaltered, but with a tendency of a minor apical shift. This occurred in all 6 treatment groups. For sites with initial probing depths of 4-6 mm and greater than 6 mm, there was in all groups some gain of probing attachment. This gain was most pronounced in the initially deeper (greater than 6 mm) pockets. With the use of regression analysis, the "critical probing depth" (CPD) value (i.e. the initial probing depth value below which loss of attachment occurred as a result of treatment and above which gain of probing attachment level resulted) was calculated for each of the 6 methods of treatment used. A comparison of the CPD-values between the 6 treatment groups did not reveal any major differences.