Combining Salivary Pathogen and Serum Antibody Levels Improves Their Diagnostic Ability in Detection of Periodontitis

Background: Initiation and progression of periodontitis correlates with increased quantities of periodontitis-associated bacteria in periodontal biofilms. In the present study, the aim is to measure Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis amounts in saliva and their antibody (immunoglobulin [Ig]A and IgG) levels in serum and evaluate their diagnostic abilities, together or alone, in chronic periodontitis. Methods: The study population comprised 230 Finnish dentate adults: 84 with generalized chronic periodontitis (GCP), 65 with localized chronic periodontitis (LCP), and 81 controls without periodontitis. General and oral health information was obtained by questionnaires, interviews, and clinical and radiographic examinations. Salivary and serum samples were analyzed by quantitative single copy gene-based real-time polymerase chain reaction and multiserotype enzyme-linked immunosorbent assay, respectively. Results: Pathogen carriers suffered mostly from GCP and seldom from LCP. A. actinomycetemcomitans and P. gingivalis quantities in saliva were strongly associated with corresponding serum IgA and IgG values (P < 0.001) and with severity of disease (P < 0.001). P. gingivalis exhibited more straightforward associations among salivary bacterial burdens, corresponding antibody formation, and periodontitis severity than A. actinomycetemcomitans. The combination of information on age, sex, smoking, and P. gingivalis results provided an area under the curve of 0.817 (95% confidence interval 0.76 to 0.87, P < 0.001) for GCP. Conclusion: The combination of saliva P. gingivalis quantity with pathogen-specific host response may be used to diagnose periodontitis with high accuracy.