MPO and gingivitis: When comparing a healthy periodontium versus a gingivitis/periodontitis scenario, several studies regarding salivary biomarkers demonstrate that there are differences regarding the concentrations of inflammatory markers such as TNF-α, IL-1β, IL-6, PCR, total MMP-8 (tMMP-8), active MMP-8 (aMMP-8), MMP-9, MMP-13, (MMP-8 being the only one capable of determining severe alveolar bone loss), albumin, osteoprotegerin, and myeloperoxidase (MPO), among others.