Dental implant-associated infections are expected to be increasingly more common as the number of patients with implants for more than 10 years rises. There are 2 stages of peri-implant infection: early mucositis, consisting of inflammation of the peri-implant soft tissues without loss of supporting bone, and a more advanced form involving a loss of osseointegration, known as peri-implantitis. The estimated prevalence of this latter infection is 10% of 5-year implants and the main risk factor is previous periodontal disease. The etiopathogenesis of peri-implantitis is related with reservoirs of periodontal pathogens; however factors that lead to colonization of the implant surface or increased susceptibility to infection may also have an influence. Treatment should include removal of the bacterial biofilm, debridement of the exposed surface, and surgical regeneration of the peri-implant pocket.