Human saliva is an easily accessible biological fluid and contains a variety of disease-related biomarkers, which makes it a potential diagnostic medium. The clinical use of salivary/oral fluid biomarkers to identify oral and systemic conditions requires the development of non-invasive screening and diagnostic technologies, and is among the main goals of oral fluid researchers. The analysis of the disease-specific oral and systemic biomarkers in saliva and oral fluids (i.e., mouth-rinse, gingival crevicular fluid (GCF) and peri-implantitis sulcular fluid (PISF)) is demanding. Several factors influence their expression and release; these factors include the intracellular location, the molecular size and the flow characteristics of the biological fluid. The type of saliva/oral fluid utilized for the diagnostics affects the analysis. High sensitivity together with sophisticated methods and techniques are essential to get a useful outcome. We describe here a recently developed mouth-rinse that is practical, convenient and inexpensive, as well as PISF chair-side/point of care (PoC) lateral-flow active matrix metalloproteinase (aMMP-8) immunoassays to detect, predict and monitor the course and treatment of periodontitis and peri-implantitis.