REVIEW – November 2003

Oral microecology in chronic periodontitis


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Periodontitis is a chronic inflammation of the periodontium that is most frequently related to gram-negative anaerobic rods. The role of the other bacteria is less known. The aim the present study was to assess the association between periodontal status, experience of dental caries, and the subgingival and salivary microbial communities.
Twenty-six chronic periodontitis (CPD) and 15 periodontally healthy patients were investigated. Clinical data and salivary levels of lactobacilli and mutans streptococci were recorded. For subgingival samples, quantitative microbiological analysis was performed. Periodontopathogens A. actinomycetemcomitans, P. gingivalis and P. intermedia were detected in 54%, 23% and 73% of CPD patients, respectively, the last was found also in 47% of healthy subjects. Thus, the prevalence of P. gingivalis is relatively low as compared to the prevalence of A. actinomycetemcomitans and P. intermedia, suggesting that regional-specific differences in colonization with periodontal pathogens may exist. In both groups, mixed aerobic and anaerobic subgingival microflora was seen; the total bacterial count in CPD patients was much higher. The main differences in health and disease was observed in the mean proportion of bacterial groups: the mean proportion of aerobes and gram-positive bacteria was higher in healthy sites, while that of anaerobes and gram-negative bacteria in diseased sites. Salivary levels of lactobacilli and mutans streptococci were similar in two groups, however CPD patients were less often affected by dental caries. Thus, it is obvious that important differences in oral microecology of chronic periodontitis exist, and further studies are necessary to elucidate the potential ways to influence it.