“…A total of 21 studies comparing microbial profiles of peri‐implantitis and healthy implants were evaluated using different microbiologic methods: two used methods of cultivation, 37,40 two conventional polymerase chain reaction (PCR), 38,43 three quantitative PCR, 16,17,50 one nested‐PCR, 14 eight DNA hybridization, 9,13,27,36,39,41,42,49 and five DNA sequencing methods 18,19,44,47,51 . The major periodontopathic microorganisms (red complex: Porphyromonas gingivalis [ Pg ], Tannerella forsythia [ Tf ], and Treponema denticola [ Td ]; orange complex: Prevotella intermedia [ Pi ] and Fusobacterium nucleatum [ Fn ]; and other microorganisms: Aggregatibacter actinomycetemcomitans [ Aa ], Eikenella corrodens [ Ec ], Parvimonas micra [ Pm ], and Campylobacter rectus [ Cr ]) were identified in 11 of 21 studies (52.3%) 9,14,16,17,37,39,40,43,49,50,52 . Three studies also evaluated opportunistic microorganisms 37,40,52 .…”