The aMMP-8 and total MMP-8 results are in agreement with previous findings, e.g., Lee et al. and Romanelli et al. [10,11], that it is the collagenolytic and proteolytically active aMMP-8, and not the inactive pro-/latent species of MMP-8, that plays the more important role in the pathological periodontal tissue breakdown and progression of periodontitis. This evidence concerns the gene MMP8 and periodontitis.