Establishing cut-off values for salivary MMP-8 and IL-1β in the diagnosis of active periodontal disease: a preliminary cohort study toward the development of a diagnostic kit.

Purpose: The identification of specific target molecules and their appropriate cut-off values is crucial for the successful development of in vitro diagnostics. Salivary biomarkers, such as interleukin-1β (IL-1β) and matrix metalloproteinase-8 (MMP-8), have been investigated for their potential in diagnosing periodontal disease. This study aimed to evaluate the efficacy of IL-1β and MMP-8 as diagnostic tools and to establish their cut-off values for distinguishing active types of periodontal disease from healthy conditions.

Methods: We conducted a prospective cohort study involving 47 participants, who were divided into 2 groups: the control group consisted of 24 individuals with healthy or mild periodontal conditions (stages I-II of periodontal disease), and the periodontal group comprised 23 individuals with moderate to severe periodontal disease (stages III-IV). Saliva samples were collected from all participants, followed by an oral examination, periodontal charting, and radiographic assessments. The salivary concentrations of IL-1β and MMP-8 were quantified using enzyme-linked immunosorbent assays.

Results: Significant differences in salivary levels of IL-1β and MMP-8 were observed between the control group and those with periodontal disease. However, after adjusting for age and sex, these differences were not statistically significant for IL-1β. In contrast, the differences remained significant for MMP-8 in participants classified as having an active type of periodontal disease, specifically those in the periodontal group with more than 10% bleeding on probing. By setting a cut-off value of 200 ng/mL for salivary MMP-8, the sensitivity and specificity for diagnosing active periodontal disease were determined to be 70% and 86.5%, respectively.

Conclusions: Our findings indicate that salivary MMP-8, using a cut-off value of 200 ng/mL, serves as a reliable biomarker for identifying active periodontal disease. This biomarker holds potential for further development into a diagnostic tool in in vitro settings, which could improve the early detection and management of periodontal disease.