Salivary biomarkers of existing periodontal disease - A cross-sectional study

Background. The authors conducted a study to determine if salivary biomarkers specific for three aspects of periodontitis-inflammation, collagen degradation and bone turnover-correlate with clinical features of periodontal disease. Methods. The relationship between periodontal disease and the levels of interleukin-1 beta (IL-1 beta), matrix metalloproteinase (MMP)-8, and osteoprotegerin (OPG) in whole saliva of 57 adults (28 "case" subjects with moderate-to-severe periodontal disease and 29 healthy control subjects) was examined in a case-control trial. Results. Mean levels of IL-1 beta and MMP-8 in saliva were significantly higher in case subjects than in controls. Both analytes correlated with periodontal indexes, whereas, after adjustment for confounders, OPG did not. Elevated salivary levels of MMP-8 or IL-1 beta (more than two standard deviations above the mean of the controls) significantly increased the risk of periodontal disease (odds ratios in the 11.3-15.4 range). Combined elevated salivary levels of MMP-8 and II-1 beta increased the risk of experiencing periodontal disease 45-fold, and elevations in all three biomarkers correlated with individual clinical parameters indicative of periodontal disease. Conclusion. Salivary levels of MMP-8 and IL-1 beta appear to serve as biomarkers of periodontitis. Clinical Implications. Qualitative changes in the composition of salivary biomarkers could have significance in the diagnosis and treatment of periodontal disease.