A dysregulated inflammatory reaction by the host against local microorganisms has been observed during periodontitis and is characterized by a production of potent pro-inflammatory mediators such as IL-1β, TNF-α, IL-6, and IL-8, as well as various protein-degrading enzymes such as MMP-8, MMP-9, and MMP-13, leading to localized destruction [33, 34]. This evidence concerns the gene MMP9 and periodontitis.