Peri-implantitis is an immune-mediated biological complication that is estimated to affect 12%-24% of dental implants. Periodontal and peri-implant inflammation are associated with the presence of periodontal or peri-implant biofilms, respectively. Thus, for over a decade, peri-implantitis was treated with the antimicrobial and mechanical treatments used for periodontitis until it was realized that these treatments were ineffective. Nonetheless, despite their seemingly identical phenotypic inflammatory phenotypes that are related to bacterial biofilms, peri-implant inflammatory disease may be singular both in terms of pathogenic microbiome composition and molecular inflammatory characteristics.