Analysis of the periodontal microbiota in childhood-type hypophosphatasia

Seven patients with childhood-type hypophosphatasia and healthy control subjects were analysed for microbiological and clinical evidence of periodontitis. The bacterial composition of the subgingival plaque was analysed by 16S rRNA gene cloning and sequencing, DNA-DNA hybridisation with specific probes, and specific PCR. With the exception of the genus Veillonella and the species Eikenella corrodens, no differences between the cohorts in the composition of bacterial orders, families, genera, and species were observed. Accordingly, patients showed only slightly more bleeding on probing (BOP), and slightly higher periodontal probing depth (PPD) values than controls. Although this pilot study did not have the power to assess the prevalence of periodontitis in HP, we suggest that most paediatric patients suffering from HP harbour a subgingival microbiota, which is comparable to that of the healthy population.

Molecular epidemiology of oral treponemes in patients with periodontitis and in periodontitis-resistant subjects

The etiologic role of oral treponemes in human periodontitis is still under debate. Although seen by dark-field microscopy in large numbers, their possible role is still unclear since they comprise some 60 different phylotypes, most of which are still uncultured. To determine their status as mere commensals or opportunistic pathogens, molecular epidemiological studies are required that include both cultured and as-yet-uncultured organisms. Here we present such data, comparing treponemal populations from chronic periodontitis (CP) or generalized aggressive periodontitis (GAP) patients. As a periodontitis-resistant (PR) control group, we included elderly volunteers with more than 20 natural teeth and no history of periodontal treatment and no or minimal clinical signs of periodontitis. Almost every treponemal phylotype was present in all three groups. For most treponemes, the proportion of subjects positive for a certain species or phylotype was higher in both periodontitis groups than in the PR group. This difference was pronounced for treponemes of the phylogenetic groups II and IV and for Treponema socranskii and Treponema lecithinolyticum. Between the periodontitis groups the only significant differences were seen for T. socranskii and T. lecithinolyticum, which were found more often in periodontal pockets of GAP patients than of CP patients. In contrast, no difference was found for Treponema denticola. Our findings, however, strengthen the hypothesis of treponemes being opportunistic pathogens. It appears that T. socranskii, T. lecithinolyticum and group II and IV treponemes may represent good indicators for periodontitis and suggest the value of the respective probes for microbiological diagnosis in periodontitis subjects.

Chronic periodontal disease is associated with single-nucleotide polymorphisms of the human TLR-4 gene

Periodontitis is an inflammatory disease affecting the connective tissue surrounding the teeth leading to tooth loss. Pathogens associated with periodontitis interact with Toll-like receptors (TLRs) to induce cytokines causing and aggravating disease. We screened 197 individuals suffering from generalized periodontitis for the presence of Asp299Gly and Thr399Ile of TLR-4 as well as Arg753Gln of TLR-2 in comparison to matched controls. Single-nucleotide polymorphisms (SNPs) of TLR-4 were elevated among patients (odd's ratio 3.650, 95% CI 1.573-8.467, P < or = 0.0001), while no difference was observed for TLR-2. TLR-4 SNPs were correlated with chronic periodontitis (odd's ratio 5.562, 95% CI 2.199-14.04, P < or = 0.0001), but not with aggressive periodontitis. This observation was confirmed employing a group of periodontally healthy probands over 60 years of age. These data demonstrate that genetic variants of TLR-4 may act as risk factors for the development of generalized chronic periodontitis in humans.

Aspartat aminotransferase--a marker of periodontal disease activity

Active and inactive periodontal pockets exist in periodontal disease and the progression of periodontitis is episodic and cyclical. Current diagnostic tests do not distinguish between active and inactive lesions. Objective assessment of disease activity could significantly affect periodontal therapy. Aspartat aminotransferase (AST) activity in gingival crevicular fluid is a potential quantitative marker of periodontal disease activity. Thirty-six patients with periodontitis, twenty with adult periodontitis and sixteen with rapidly progressive periodontitis were evaluated clinically prior to treatment and AST activity in periodontal pockets was determined prior to and after initial therapy. Clinical measures included plaque index, gingival inflammation degree and attachment loss. The results show that AST levels do not correlate with clinical indices and that they decrease after treatment. AST is a possible novel biochemical marker of periodontal disease activity independent of commonly used clinical measures. It could also be useful for early monitoring of treatment success.

Inflammatory mediators in saliva of patients with rapidly progressive periodontitis during war stress induced incidence increase

Rapidly progressive periodontitis (RPP) results from the interaction between the periodontal microflora and the host. Stress is believed to play an important role in determining host responses, and it has been proposed that hyperactivity of host defense mechanisms significantly increases tissue destruction typical for this disease. During a period of four months we have diagnosed 20 patients with acute RPP, all of them active participants in battles of the Croatian liberation war with posttraumatic stress disorder (PTSD) related symptoms. In these patients we analyzed biochemical parameters in unstimulated saliva and performed microbiological analyses of periodontal pockets. These findings were compared with those of patients with adult periodontitis (AP), edentulous and healthy persons, none of whom participated in the war. Persons with AP had reduced concentrations of host humoral defense factors in saliva (C-reactive protein, C3 component of complement, and aplha alpha 2-macroglobulin), while patients with RPP had increased concentration of interleukin-6 (IL-6). IL-6 is released by host inflammatory cells and is a mediator of bone resorption. Actinobacillus actinomycetemcommitans and Peptostreptococcus were more frequently isolated from patients with RPP. We interpret these results as indicators of the importance of stress in the causation of RPP, with host inflammatory hyperactivity playing an important role in tissue destruction, specially alveolar bone resorption possibly caused by increased local levels of IL-6.