Periodontal disease diagnostic methods, uses and kits

Disclosed is an in vitro method for assessing whether a human patient is free from periodontal disease, has gingivitis, has mild periodontitis or has advanced periodontitis. The method is based on the insight to determine biomarker proteins. Accordingly, in a sample of saliva of a patient, the concentrations are measured of the proteins: Alpha-1-acid glycoprotein (A1AGP) and Pyruvate Kinase (PK), and at least one of the proteins Matrix metalloproteinase-9 (MMP-9) and S100 calcium binding protein A8 (S100A8). Based on the concentrations as measured, at least one value is determined reflecting the joint concentrations for said proteins. This at least one value may indicate the probability that human patient is free from periodontal disease, has gingivitis, has mild periodontitis or has advanced periodontitis. The at least one value can be compared with at least one threshold value reflecting in the same manner the joint concentrations associated with gingivitis, mild or advanced periodontitis. The comparison allows assessing whether the testing value is indicative of the periodontal health status in said patient.