Identification and analyses of periodontal pathogens in Taiwan by microbiological tests

The purpose of this study was to use microbiological tests for diagnosis of periodontal diseases in Taiwan. Anaerobic culture, direct microscopy, indirect immunofluorescence (IF), and biochemical tests were used to examine 336 samples for the specific microorganisms in subgingival plaque. The results indicated that gram-negative species and motile bacteria were less frequently detected, and in lower proportion, in samples from healthy sites. The bacteria found frequently in healthy group were the coccal forms. However, Bacteroides forsythus detected by IF showed a close association with periodontal inflammation. Porphyromonas gingivalis was found with about 53% frequency in the periodontitis group; in more than half the samples the proportion was above 5%. Actinobacillus actinomycetemcomitans was recovered with 48% frequency of periodontitis group. Other cultivable species including Campylobacter rectus, Capnocytophaga species, Centipeda periodontii, Eikenella corrodens, Fusobacterium nucleatum, Prevotella intermedia, Selenomonas species, and the Spirochetes were detected in a significantly higher proportion in periodontitis group. The results strongly support the use of microbiological tests as adjuncts to diagnosis, and for assessment of the importance of microbiota in periodontal disease.