[Bacteriologic investigation of periodontal infections].

The gingivitis and periodontitis are very common diseases in Hungary: more than 80% of the adult population suffers with gingivitis and 15-20% has destructive periodontitis. The composition of peridontopathogenic bacterial flora is totally different from that of the bacterial flora causing dental infections. In periodontal infections dominantly facultative and obligatory anaerobic microorganisms occur (Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans), Porphyromonas gingivalis (P. gingivalis), Bacteroides forsythus (B. forsythus). The main objective of the study was to investigate the microbial flora of the rapidly progressing periodontitis with special respect to the occurrence of the Actinobacillus actinomycetemcomitans. The antibiotic susceptibility of the A. actinomycetemcomitans was also determined against the most frequently used conventional antibiotics. Twenty-five samples collected from patients with rapidly progressing periodontitis were examined. Prevalence and ratio of A. actinomycetemcomitans and other species of the periodontal anaerobic flora were investigated. MIC values of different antibiotics used routinely--clindamycin, amoxicillin/clavulanic acid, tetracycline, metronidazole--were measured. Prevalence of black pigmented bacteroides (50%), and A. actinomycetemcomitans (30%) was comparable to data of foreign investigators. A. actinomycetemcomitans spp. appear to be more sensitive to clindamycin and amoxicillin/clavulanic acid and more resistant to metronidazole compared to published data. The knowledge of microbial composition of the periodontal flora could help to diagnose the different forms of periodontitis. It can also assist the indication of the most appropriate antibiotic therapy.