It is the main collagenase involved in periodontal disease, and has the highest collagenolytic activity in GCF.20 It was reported that in people with chronic periodontitis, 80% of the collagenase in GCF samples is composed up of MMP-8.8 Neutrophils are the primary source of MMP-8 release, and they play a crucial role in the development of periodontal disease. This evidence concerns the gene MMP8 and chronic periodontitis.