Die systemische Verabreichung von Amoxizillin/Metronidazol (AM) als Zusatz zu Scaling/Root planing (SRP) in der Behandlung der generalisierten Aggressiven Parodontitis (gAP) führt zu guten klinischen und mikrobiologischen Ergebnissen. Die lokale antiseptische Zusatzmedikation mit Chlorhexidin in einem Controlled-Delivery-Device (PerioChip, PC) verbessert das Ergebnis von SRP in der Behandlung der Chronischen Parodontitis. Die Anwendung in der Behandlung der gAP ist bisher noch nicht untersucht worden. Ziele: Der Effekt von PC als Zusatz zu SRP in der Therapie der gAP wurde untersucht. Die Wirksamkeit wurde mit der Standardmedikation AM verglichen. Neben klinischen Parametern wurde die Konzentration des Entzündungsmarkers Calprotectin in der Sulkusflüssigkeit (SF) bestimmt. Material/Methode: 36 gAP-Patienten (18/Gruppe, 35+/-4 Jahre) wurden mit SRP und randomisiert entweder mit AM oder PC behandelt. Zur Baseline, 3 und 6 Monate nach SRP wurden die klinischen Parameter PD, CAL, BoP, Pus erhoben sowie SF-Proben tiefer und flacher Referenzstellen entnommen. Die Calprotectin-Konzentration in der SF wurde mittels ELISA bestimmt. Ergebnisse: 3 Monate nach SRP zeigten beide Gruppen signifikante Verbesserungen der klinischen Parameter, wobei noch keine Unterschiede zwischen den Gruppen bestanden. Während die AM-Gruppe stabil blieb, verschlechterten sich mehrwurzelige Zähne und tiefe Referenzstellen der PC-Gruppe wieder signifikant. Nach 6 Monaten wies die AM-Gruppe signifikant mehr CAL-Gewinn und PD-Reduktion auf. Pus war nur noch in der PC-Gruppe nachweisbar. Die Calprotectin-Konzentration war zwar in beiden Gruppen signifikant gesunken, Unterschiede zwischen den Gruppen bestanden jedoch aufgrund hoher Standardabweichungen nicht. Schlussfolgerung: AM zeigte eine bessere klinische Wirksamkeit und Langzeitstabilität als PC. Aufgrund großer interindividueller Variabilität spiegelte die SF-Konzentration von Calprotectin die klinischen Unterschiede nicht wider. / Adjunctive systemic administration of amoxicillin/metronidazole (AM) in generalized aggressive periodontitis (gAP) therapy results in good clinical and microbiological outcome. Adjunctive use of chlorhexidine within a controlled-delivery-device (PerioChip, PC) improves the outcome of scaling/root planing (SRP) in chronic periodontitis therapy. Its effect in the treatment of gAP has not been evaluated. Aims: The effect of adjunctive use of PC in the treatment of gAP was investigated. Efficacy of PC was compared to the standard treatment with AM. Clinical parameters and the concentration of the inflammation marker calprotectin within gingival crevice fluid (GCF) were measured. Material/methods: 36 gAP patients (18/group, 35+/-4 years) were treated by SRP either AM or PC. Clinical parameters PD, CAL, BoP and Pus were recorded at baseline, 3 and 6 months after therapy. GCF was sampled at deep and shallow reference sites and the concentration of calprotectin was measured by ELISA. Results: Both groups showed significant improvements of clinical parameters 3 months after SRP, however differences between groups were not significant. While the AM-group remained clinically stable, multirooted teeth and deep reference sites of the PC-group showed significant deterioration again. 6 months after SRP, the AM-group showed significant more CAL gain and PD reduction. Pus was detectable in the PC group only. The concentration of calprotectin in GCF had significantly decreased in both groups; however differences between groups were not significant due to high standard deviations. Conclusion: AM showed higher efficacy in terms of clinical treatment outcome and long-term stability than PC. Due to high interindividual variability, GCF-concentrations of calprotectin failed to reflect clinical differences.

Marginale Parodontitis, die multikausale Erkrankung des Parodonts ist eine Infektionskrankheit, modifiziert durch Wirtsfaktoren und äußere Einflüße. Die als pathogene Mischflora bezeichnete Kombination kommensaler Mikroorganismen spielt die primäre Rolle in der Ätiopathogenese der Parodontitis. In der Aufstellung des Studienziels wurden einzelne Bakterienarten (T. forsythensis, P. gingivalis, A. actinomycetemcomitans, C. rectus, F. nucleatum, Fusobacterium spp., P. intermedia, E. corrodens, V. parvula und C. ochracea) ausgewählt, die eventuell als "Markerkeime" in der aggressiven Form der Parodontitis betrachtet werden können. Dazu wurde eine Kontrollgruppe untersucht, die eine gesunde parodontale Flora besitzt. Die angewandte Nachweismethode basiert auf der PCR-Amplifikation von 16S rDNA und darauffolgender dot-blot Hybridisierung mit Oligonukleotidsonden. Die entsprechenden Sonden wurden hergestellt, optimiert und evaluiert. Für die epidemiologische Untersuchung wurde subgingivale Plaque von vier Parodontaltaschen und einer Kontrollstelle von 45 Patienten mit aggressiver Parodontitis, sowie an fünf Stellen von 21 Senioren entnommen. Die Prävalenz der einzelnen Bakterienarten wurde mit Hilfe des Chi-Quadrat Test verglichen. Obgleich eine hohe interindividuelle Variabilität der Kolonisationsmuster zu beobachten war, konnten T. forsythensis, P. gingivalis, C. rectus und F. nucleatum signifikant häufiger in den Parodontaltaschen als an den gesunden Stellen nachgewiesen werden und können deswegen als "Leitkeime" der aggressiven Parodontitis angesehen werden. A. actinomycetemcomitans konnte nur bei einzelnen Patienten mit aggressiver Parodontitis festgestellt werden. Die Ergebnisse für P. intermedia und E. corrodens ließen keine eindeutige Assoziation sowohl mit der aggressiven Parodontitis als auch mit dem gesunden Parodontalzustand zu. Bei Senioren wurde C. ochracea besonders häufig nachgewiesen. Die Ergebnisse dieser Studie bewiesen die erfolgreiche Einsetzbarkeit der hergestellten Oligonukleotidsonden. / A multifactorial risk pattern of periodontitis has been recognized, where in addition to host and environmental factors, a pathogenic microbiota plays a primary role. The purpose of the current research was to analyze the prevalence of periodontitis-associated microorganisms in patients with aggressive periodontitis and periodontally healthy elders by using molecular-biologic detection methods like eubacterial PCR-amplification of 16S rDNA in combination with dot-blot hybridization. The oligonucleotide probes for the detection of T. forsythensis, P. gingivalis, A. actinomycetemcomitans, C. rectus, F. nucleatum, Fusobacterium spp., P. intermedia, E. corrodens, V. parvula and C. ochracea were designed and evaluated. The PCR products of 42 cultivated target and closely related bacteria were used for the optimization of hybridization conditions. For the epidemiological study, subgingival plaque was sampled from four pockets and one healthy site of 45 aggressive periodontitis patients as well as from five sites of 21 elderly. The differences in the prevalence of bacterial species were analyzed by the chi-square test. The data revealed frequent colonization by T. forsythensis, P. gingivalis, F. nucleatum and C. rectus in patients with aggressive periodontitis, however individual variations were obvious. These species could be predominantly identified in periodontal pockets, but were significantly less common in the healthy sites of the periodontitis patients and in the elderly. These putative pathogens can be conclusively determined as the key-bacteria in patients with aggressive periodontitis. No direct association for P. intermedia and E. corrodens with aggressive periodontitis or periodontal health could be seen. A. actinomycetemcomitans could be detected in only a few patients, reducing its suspected importance in the etiology of aggressive periodontitis. C. ochracea was highly prevalent in the well-maintained elderly, suggesting its association with healthy flora. The results of the study confirmed the reliability of the oligonucleotide probes in a specific and sensitive detection of the respective oral species.

Actinobacillus actinomycetemcomitans is present in elevated proportions and numbers in dental bacterial biofilms of patients with localized aggressive periodontitis. This variant of periodontal disease, occurring in adolescents and young adults, is characterized by rapid and severe destruction of the connective tissues and bone supporting the teeth, eventually culminating in tooth loss. The cytolethal distending toxin (Cdt) is a newly discovered bacterial protein toxin, uniquely present in A. actinomycetemcomitans among all known to-date oral bacterial species. The Cdt has the capacity to inhibit mammalian cell growth, but its putative role in the pathogenesis of the disease is unclear. The aim of this in vitro work has been to study the effects of A. actinomycetemcomitans on periodontal connective tissue cell cultures, and to evaluate the possible involvement of its Cdt. A. actinomycetemcomitans inhibited the proliferation of gingival and periodontal ligament fibroblasts, as a result of a combined arrest at the G1 and G2/M phases of the cell cycle. This growth inhibition was non-lethal and the cells remained metabolically active, although their DNA synthesis was reduced. The intoxicated cells exhibited increased size and irregular structure, characterized by distension and elongation. This cellular enlargement occurred in both G1 and G2/M phase arrested cells. The Cdt of A. actinomycetemcomitans was responsible for the observed growth inhibition, as well as the concomitant morphological alterations. The possible induction of inflammatory cytokines related to bone resorption was investigated in response to A. actinomycetemcomitans, and the involvement of Cdt was evaluated. Extensive focus was given to the study of receptor activator of NF-κB ligand (RANKL) expression, a membrane-bound ligand that signals osteoclast progenitors to differentiate and fuse into mature osteoclasts, activating bone resorption. It was demonstrated that A. actinomycetemcomitans induced RANKL mRNA and protein expression in the cells studied, but did not affect the expression of its decoy receptor, osteoprotegerin. This induction was solely attributed to its Cdt, as demonstrated by the use of a cdt-knockout A. actinomycetemcomitans strain, purified recombinant Cdt, and antibodies blocking the Cdt. In addition, this event was not mediated by pro-inflammatory cytokines known to stimulate RANKL. Interleukin-6 mRNA and protein expression were also enhanced by A. actinomycetemcomitans, but Cdt had limited involvement in this enhancement. In conclusion, two distinct mechanisms by which A. actinomycetemcomitans Cdt may be involved in the pathogenesis of localized aggressive periodontitis are proposed. Firstly, the growth arrest of the resident fibroblasts may impair the physiological connective tissue remodelling equilibrium and lead to connective tissue attachment loss. Secondly, the induction of RANKL by these cells, residing in the proximity of the alveolar bone, may locally stimulate osteoclastogenesis and promote alveolar bone resorption. This work also provides further insights to the understanding of Cdt mechanisms of action, contributing to the global characterization of the toxin’s virulence.

The Gram-negative bacterium Aggregatibacter actinomycetemcomitans is primarily associatedwith aggressive forms of periodontal disease. Additionally, it has occasionally been found to causemetastatic infections in non-oral sites. This requires the ability to evade the bactericidal activity ofthe complement system of the humoral immune system. Outer membrane proteins, namely,Omp100 and OmpA have been connected to normal human serum resistance for several bacteriaspecies. The objective of this study was to investigate if serum-resistant ompA mutants can beobtained, and to detect changes in OMP expression. We used A. actinomycetemcomitansserotype a strain D7SS and D7SS ompA knockouts. The strains were incubated in 50 % NHS.This resulted in a substantial decrease of survival among D7SS ompA knockouts. D7SS ompAknockouts were exposed to 50 % NHS once more to confirm stable serum resistance. 13 out of14 tested clones showed growth, indicating that serum resistant ompA mutants could begenerated. SDS-PAGE gel of extracted outer membrane vesicles revealed an additional proteinband of approximately 34 kDa in at least 4 of 5 tested serum resistant ompA mutants. This proteinband has been analyzed in the laboratory, and according to LC-MS/MS it contains an OmpAhomologue, which has been named OmpA2. We conclude that OmpA2 expression might be amajor mechanism for serum survival in A. actinomycetemcomitans serotype a strain D7SS ompAknockouts.