Decrease of sulfate-reducing bacteria after initial periodontal treatment.

Sulfate-reducing bacteria (SRB) are associated with periodontitis, but it is unknown if elimination of these potential pathogens accompanies clinical improvement. This longitudinal study examined the occurrence of SRB and clinical effects following scaling and root planing. In this study, the presence of periodontal SRB was determined in 38 selected patients before and six months after mechanical therapy. SRB were detected by the enrichment culture technique. Mechanical periodontal treatment resulted in elimination of SRB in 89% of the patients, and 95% of the sites (n = 76). SRB were significantly reduced in patients with progressive, adult, and refractory periodontitis. The elimination of SRB was accompanied by clinical improvement. The mean gain of attachment of these pockets was 3 mm (p < 0.001). The reductions in pocket depth (p < 0.001) and bleeding were significant (p < 0.001). Persistence of SRB correlated with the initial pocket depth (p < 0.02) and attachment level (p < 0.02), and with bleeding of the site after treatment (p < 0.05). In conclusion, mechanical debridement is generally effective for the elimination of SRB.

Sulfate-reducing bacteria in association with human periodontitis.

BACKGROUND, AIMS: Sulfate-reducing bacteria (SRB) may be etiologically involved in destructive periodontal diseases. These strictly anaerobic bacteria utilize fermentation products for energy conservation by reduction of sulfate to sulfide. This toxic product can accumulate in periodontal pockets in concentrations causing cellular destruction. SRB depend on an actively degrading microbiota to produce a reduced environment, fermentation products and sulfate. The detection frequency of these bacteria is strongly increased in periodontitis compared with healthy sites in the oral cavity. METHOD: In this study, the presence of SRB was determined in relation to clinical features of the patients and to site-specific clinical parameters of periodontitis, such as pocket depth, bleeding and attachment level. Patients with clinical characteristics of severe periodontitis (n=87) were included in the study, 78 were untreated patients and 9 patients were in maintenance care after treatment. Samples were taken (n=261) from the deepest periodontal pockets, and presence of SRB was determined by enrichment culture in an anoxic chamber. RESULTS: In 64% of the patients, SRB were present in at least 1 pocket. They occurred among patients from 23 to 57 years old, and tended to prevail among patients older than 30 years. There was a tendency to increased SRB occurrence among patients with more than 50% of bleeding sites, or with several angular bony defects or furcations. In 44% of the periodontal pockets SRB were present. They tended to prevail in pockets showing bleeding on probing, furcations, angular bony defects, or an endodontal complication. Presence of SRB was positively correlated with increased pocket depth (p<0.05). SRB were found to be associated with various clinical categories of periodontitis, including early onset periodontitis, rapidly progressive periodontitis, adult periodontitis, and refractory periodontitis. Although SRB predominated among patients with an adult form of periodontitis, i.e., with an occurrence of 72%, there was no significant correlation with age of the patient. Among treated patients under maintenance care, SRB prevalence was significantly reduced in comparison with untreated patients (p<0.02). Occurrence of SRB in periodontal pockets showed an odds ratio of 11.2 in comparison with healthy oral sites. CONCLUSION: Periodontal sulfate-reducing bacteria are associated with several clinical categories of periodontitis and with periodontal sites of increased pocket depth.