Subgingival microflora and periodontitis

Abstract

Predominant bacterial flora resident in subgingival plaque was characterized and evaluated in relation to the etiology of periodontal disease. Small groups of clinically and radiographically identified periodontal patients and control subjects were studied. A comprehensive inventory of cultivable flora was made. The most common group of organisms were the Gram‐positive rods, the majority of which were Actinomyces . A larger proportion of anaerobic Gram‐negative rods were isolated than indicated in the results of previous studies. Considerable variability in floral content was found in different sites in the same patient. However, no statistically significant differences were observed in the flora between clinically normal and pathological sites of the same patients. A significantly greater number of facultative Actinomyces was present in the flora of periodontal patients as compared to control subjects. Sera from the same nine subjects were assayed by indirect immunofluorescence for circulating antibodies to 12 strains of plaque bacteria. No differences in antibody titers were observed between sera from periodontal patients and control subjects.