MMP8 and periodontitis: The cumulative risk score (CRS) for periodontitis consists of three salivary biomarkers: Porphyromonas gingivalis, interleukin (IL)‐1β and matrix metalloproteinase (MMP)‐8 (Gürsoy et al. 2011), with IL‐1β reflecting inflammation, MMP‐8 tissue destruction and P. gingivalis periodontal pathogen burden.