Prediction of P. gingivalis Using the Periodontal Index and Serum Antibody Level

Objectives: Chronic periodontitis is an inflammatory disease induced by pathogenic bacterial accumulation. P. gingivalis is a critical periodontal pathogen responsible for progression of this disease. We aimed to reconstruct a model that predicted P. gingivalis expression using the periodontal inflamed surface area (PISA) and the serum P. gingivalis antibody level. PISA represents the sum of the periodontal pocket depth of bleeding on probing-positive sites and is a useful index for distinguishing an active inflammation from a resting state of the periodontium.
Methods: In this study, 84 systemically healthy subjects were recruited for the control group of an ankylosing spondylitis (AS) cohort study. The subjects underwent periodontal examinations, and their subgingival plaque and peripheral blood samples were collected to examine the P. gingivalis expression and serum antibody level.
Results: The PISA values of each subject significantly correlated with conventional periodontal classifications (correlation coefficient=0.52, p<0.001) and with periodontal indexes, such as bleeding on probing (BOP; correlation coefficient=0.94, p<0.001) and the plaque index (correlation coefficient=0.56, p<0.001). In a multivariable logistic regression predicting P. gingivalis expression, PISA and the serum antibody level of P. gingivalis were significant factors (PISA, p=0.002; serum antibody, p=0.001). The odds ratio for PISA was associated with a 1.31-fold increase in P. gingivalis expression, and the serum antibody level was associated with a 1.18-fold increase.
Conclusions: Therefore, periodontal examination combined with serum antibody level could be a useful tool for the accurate diagnosis of periodontal disease.