Objective: To investigate the prevalence of 3 anaerobic microorganisms including Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf) and Treponema denticola (Td) in saliva and pooled subgingival plaque of different types of periodontitis and compare the detections of three microorganisms between saliva and pooled subgingival plaque sample from the same patient, and analyze the relationship between prevalence of these pathogens in saliva and periodontal parameters.
Methods: Non-stimulated saliva samples and pooled subgingival plaque samples were collected from 50 patients with aggressive periodontitis (AgP), 48 patients with chronic periodontitis (CP) and 25 subjects with no periodontitis, and three microorganisms including Pg, Tf and Td were detected in these samples by PCR method.
Results: Prevalence of three microorganisms in pooled subgingival plaque and saliva samples of AgP patients and CP patients were significantly higher than subjects with no periodontitis (P<0.01). The prevalence of Pg in Subgingival plaque and saliva was as follows: AgP, 100% vs 100%; CP, 93.8% vs 93.8%; Subjects with no periodontitis, 32% vs 48%. The prevalence of Tf in Subgingival plaque and saliva was as follows: AgP, 96% vs 88%; CP, 97.9% vs 89.6%; Subjects with no periodontitis, 32% vs 24%. The prevalence of Td in Subgingival plaque and saliva was as follows: AgP, 94% vs 86%; CP, 89.6% vs 70.8%; Subjects with no periodontitis, 12% vs 16%. The agreement between saliva and pooled subgingival plaque samples of these three microorganisms from the same patient was high. The presence of three microorganisms in saliva was all associated with bleeding index of gingiva, and odds ratio of Pg was 13.5 (P<0.01).
Conclusion: Pg, Tf and Td were widely distributed in saliva and subgingival plaque of patients with AgP and CP. Presence of Pg, Tf and Td in saliva was related to periodontal parameters of gingiva, and saliva could be used as a promising sample for oral detection of these 3 microorganisms.