Clinical, microbiological, and immunological studies following initial preparation in adult periodontitis.

This study investigated the clinical, microbiological and immunological changes induced in adult periodontitis by initial preparation. Microflora in periodontal lesions was mainly examined by cultural methods, and serum IgG antibody levels were measured by an enzyme linked immunosorbent assay. Black-pigmented gram negative anaerobes, especially Porphyromonas (Bacteroides) gingivalis, was predominant in periodontal pockets with adult destructive periodontitis. Significantly elevated serum IgG antibody levels to P. gingivalis was found in high frequency, and these serum IgG antibody levels correlated with the presence of P. gingivalis in periodontal pockets, not with other bacteria tested. Total-CFU was significantly reduced and clinical conditions were improved after supragingival plaque control, but the microflora themselves showed few changes. Although reduction of total-CFU and changes in microflora were observed following scaling and root planing, it was found to be difficult to completely eliminate periodontopathic bacteria from periodontal pockets. Although serum IgG antibody levels to P. gingivalis was significantly reduced following initial preparation, the levels were still elevated from those of the controls. It was found that the presence of P. gingivalis was correlated with clinical conditions, including bleeding on probing and residual pocket depth following initial preparation.