This study examined the relationship between specific polymorphisms of the MMP-8 gene (−799C/T, −381A/G, and +17C/G) and peri-implantitis, as well as their correlation with clinical parameters such as the probing depth (PD), clinical attachment loss (CAL), and bleeding on probing (BOP). The gene discussed is MMP8; the disease is Peri-Implantitis.