Matrix metalloproteinases (MMPs) are a large family of Ca2+and Zn2+dependent proteolytic enzymes, able to cleave the various components of the extracellular matrix (ECM), as well as a range of other regulatory molecules. Several reports have proven the important role of both MMPs and their endogenous inhibitors, TIPMs, in oral health, the initial development of the tooth, and during enamel maturation. In this mini-review, we aim to summarize the literature information about the functions of MMPs, paying more attention to MMP-8 (collagenase-2 or neutrophil collagenase) in the development and progression of periodontitis, peri-implantitis, and carious lesions. We also emphasize the role of particular gene variants inMMP8as predisposing factors for some oral diseases.