[Detection of anaerobes and drug sensitivity from the periodontal pockets of patients with combined periodontal-endodontic lesions].

PURPOSE: To investigate the correlation between the composition of bacterial flora isolated from deep periodontal pockets with combined periodontal-endodontic lesions, and to test the antibiotic susceptibility of anaerobes. METHODS: Microbial samples were taken from 82 deep periodontal pockets with combined periodontal-endodontic lesions using adequate techniques, and divided into two groups: endo-perio group and perio-endo group. Antibiotic susceptibility of cultivable anaerobes were tested with agar dilution method. RESULTS: Eighty-six cultivable anaerobes were isolated, including Streptococcus spp, Prevotella spp, Actinomycetes spp, Veillonella spp, Fusobacterium spp and etc. 53.4% were gram-positive anaerobes, while 46.51% were gram-negative anaerobes. The detection rate of anaerobes in endo-perio group and that in perio-endo group had significant difference. Most isolated anaerobes were sensitive to six drugs. The resistance rates of penicillin, clindamycin, metronidazole were 6.8%, 13.9% and 2.2%. CONCLUSIONS: There is a close relationship between anaerobes and combined periodontal-endodontic lesions. Drug sensitive susceptibility should be detected prior to clinical treatment of combined periodontal-endodontic lesions.