Dental implant placement is a predictable and widely used procedure in modern dentistry. Nevertheless, several factors can negatively affect the functioning and duration of implant restoration. Considering the significant data supporting the role of the microbial factor in the development of tissue inflammation around the prosthesis, the purpose of this review was to investigate the etiological structure of implant loss from a microbiological point of view. Materials and methods. We conducted a comprehensive content analysis of scientific publications available in the PubMed/MEDLINE and Google Scholar databases. Results and discussion. Six groups of microorganisms are known as potential contributor to the dental biofilm. These groups are designated by a specific color – yellow, green, purple, orange and red. The orange and red groups include pathogens of periodontal inflammation, and also play a significant role in the development of peri-implant (PI) inflammation. Implants and teeth share histopathological and ecological similarities, thus, we can suggest that the microbial communities around these structures are similar. In the studies, the composition of the PI-associated complex of microorganisms including Porphyromonas gingivalis, Porphyromonas endodontalis, Tannerella forsythia, Filifactor alocis, Fretibacterium fastidiosum, Desulfobulbus spp. and Treponema lecithinolyticum was decsribed. It has been reported that the PI microbiome is specific to the site where an implant is placed, and the microbial composition of the biofilm of the contralateral healthy sites is more similar to the spectrum of healthy prostheses, including other subjects, than those from the same oral cavity. We can suggest that the changes in the implant microbiocenosis are dynamic. Several studies have shown the long-term consequences of dental implant restoration that can include the modification of the microbiome consisting in the progressive increase of P. gingivalis, T. forsythia, A. actinomycetemcomitans and Prevotella intermedia within 3-6 months following the procedure of implant placement. There is also an opinion about the peculiarities of the biofilm microbiota of the peri-implant tissues in case of early and late loss of the dental prosthesis. Bacteria are an important component of the microbiocenosis in any ecological niche, but the role of archaea is often overlooked. Methanogenic archaea, and Methanobrevibacter oralis are components of the normal oral microbiome, but their considerable prevalence may also be associated with peri-implant tissue inflammation. Conclusions. We have elucidated the complex nature of microbial communities within peri-implant sites and established an association between peri-implant diseases and the dysbiosis of subgingival microbial communities. Our study underscores the pivotal role of microbiota in peri-implant diseases.