Salivary Enzyme and Cytokine Concentrations in Detection of Periodontitis

Objectives: Saliva is considered as an easily collected, non-invasive specimen for screening various aspects of oral health. Our case-control study was aiming to find enzyme(s) and/or cytokine(s) that would reflect periodontal health status and related bacteria present in saliva. In addition, the effect of smoking on salivary cytokine and enzyme concentrations was evaluated. Methods: Salivary specimens originated from 165 subjects (participants in the Finnish population survey “Health 2000”) with at least 20 teeth; 85 of the subjects had advanced periodontitis (at least 14 teeth with probing pocket depth 4 mm or more) and 80 subjects were periodontally healthy. Elastase, lactate dehydrogenase (LDH), interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α activities were measured using colorimetrical tests or ELISA. The presence and number of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Treponema denticola (Td), and Tannerella forsythensis (Tf) in saliva was analyzed with quantitative PCR. Results: Salivary IL-1β concentration was higher in the periodontitis group than in the healthy group (p<0.001). In non-smokers, LDH concentration was higher in periodontitis subjects than in healthy controls (p=0.030). In general, smokers had lower LDH concentration (p<0.001) and higher IL-1β concentration (p=0.001) than non-smokers. Concerning bacterial findings, elastase concentration was higher in Aa-positive (p=0.006) and Pg-positive (p=0.043) subjects, while IL-1β concentration was higher in Tf-positive (p=0.010) subjects when compared to subjects without these bacteria. IL-1β concentrations increased in parallel with the genome numbers of Pg (p=0.008) and Tf (p=0.000), as well as with the simultaneous presence of multiple pathogenic species (p=0.031). Conclusions: Increased salivary IL-1β concentration may be used as a marker of periodontitis both in smoking and non-smoking subjects but LDH in non-smokers only. Elastase and IL-1β concentrations appear to correlate with the number of periodontal pathogens in saliva.