Recurrent periodontal disease and bacterial presence in the gingiva.

Previous investigations have shown that, in biopsies taken from untreated sites of periodontitis, bacteria were present between the epithelial cells and within the connective tissue. In the present study we have examined Gram-stained sections of diseased gingival sites where the disease had recurred after surgical periodontal treatment. The six subjects chosen for the study were patients who had undergone surgical therapy for the treatment of periodontitis and who, upon subsequent recall visits, showed evidence of at least one site recurrent after treatment as detected by bleeding on probing and increased pocket depth of 5 mm or more. A normal control site from the same patient was chosen, preferably contralaterally, showing positive response to treatment with no signs of disease. Sections were stained with either hematoxylin and eosin for tissue survey or Gram for assessment of bacteria and examined by light microscopy. In many specimens, the bacterial nature of Gram-stained material was substantiated. Preliminary results showed a significantly increased number of bacteria in the refractory sites when compared with control sites which responded positively to treatment. The results of this investigation provided further evidence that bacterial presence inside the periodontal tissue may be an important pathogenic factor in periodontal disease.