In relation to peri-implantitis, Rakic et al. (27) observed in a recent study of 369 Caucasian patients that the presence of the AG genotype in the polymorphic region of TNFα (308-) A/G was significantly higher in individuals with peri-implant pathology, with the positive patients displaying five times higher risk for peri-implantitis. This evidence concerns the gene TNF and Peri-Implantitis.