AbstractBackgroundPeri‐implant health is characterized by the absence of clinical signs of soft tissue inflammation. Peri‐implant diseases are initiated by the presence of bacterial biofilms and share a similar etiology as that involved in the onset of periodontal diseases.PurposeTo summarize available evidence on the physiopathology of peri‐implant diseases with emphasis on similarities and differences with periodontal diseases.Materials and MethodsEvidence on the biologic mechanisms involved in the pathogenesis of peri‐implant mucositis and peri‐implantitis were explored in the recent scientific literature.ResultsFindings of studies in animals and in humans indicate that experimental peri‐implant mucositis leads to a larger inflammatory connective tissue infiltrate and to a higher frequency of bleeding sites around implants compared with teeth. Tissue destruction at experimental peri‐implantitis sites is more pronounced compared with that at experimental periodontitis sites. Although human periodontitis and peri‐implantitis lesions share similarities with respect to etiology and clinical features, they represent distinct entities from a physiopathologic point of view.ConclusionsDiagnosis of peri‐implant health requires a clinical examination to confirm absence of peri‐implant soft tissue inflammation. In order to make a correct diagnosis and select the appropriate therapeutic steps to manage peri‐implant diseases, knowledge of their pathogenetic mechanisms is required.