Microbiological Markers for Prediction and Assessment of Treatment Outcome Following Non‐Surgical Periodontal Therapy

Background: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Bacteroides forsythus are considered major putative periodontal pathogens. However, it remains unclear what combinations or what levels of these bacteria influence treatment outcome. The purpose of the present study was to establish useful pathogenic markers for prediction and assessment of treatment outcome following scaling and root planing (SRP). Methods: A total of 1,149 sites in 104 chronic periodontitis patients were clinically examined at baseline. Three months after SRP, 606 sites in 56 of these patients were reexamined. Subgingival plaque samples taken from the examined sites at baseline and 3 months were analyzed for the detection and quantification of A. actinomycetemcomitans, P.gingivalis, and B. forsythus using a colorimetric polymerase chain reaction technique. Results: At baseline, high levels and a combination of P.gingivalis and B. forsythus were frequently detected in diseased sites (74%). SRP reduced the levels and the coexistence of P.gingivalis and B. forsythus (from 75% to 43%). However, in treated sites where there was less reduction of probing depth (