MICROBIAL ECOLOGY IN HEALTH AND DISEASE VOL. 9: 359-365 (1996) Gingivitis and the Initial Periodontal Lesion

This project aimed to determine which subgingival microbial species characterised clinically healthy sites, gingivitis sites, and sites that showed increase in periodontal probing depth. Fifteen medically healthy adults with minimal periodontal attachment loss were monitored clinically for 8 to 12 mths, at 2 to 3 mth intervals. Microbial samples were taken from 20 sites using strict anaerobic methods, and the predominant cultivable microbiota determined. Six subjects showed increases in probing depth measurements, and were considered putative active subjects. Cluster analysis of species colonising sites separated sites into two major groups. Actinomyces naeslundii, and Campylobacfer gracilis were in both cluster groups. Mean gingivitis levels were higher in cluster 1, which was characterised by Peptostreptococcus micros, eubacteria and Campylobacter rectus, whereas cluster 2 sites, were differentiated by Streptococcus oralis and higher levels of Actinomyces naesfundii. Healthy sites were characterised by S. oralis and S. gordonii, whereas gingivitis sites harbored higher proportions of Prevotella nigrescens, Actinomyces israelli, C. rectus, and Prevotella denticola. Subjects with suspected active sites harbored higher proportions of A. isrizefii, P. nigrescens, and Selenomonas nosia, compared with inactive subjects. These latter species are candidates for the initiation of periodontal loss. KEY WORDS: periodontitis; microbiology; bacteria