Revisiting Socransky’s Complexes: A Review Suggesting Updated New Bacterial Clusters (GF-MoR complexes) for Periodontal and Peri-Implant Diseases and Conditions
Authors: Fernandes Gustavo Vicentis Oliveira , Mosley Grace , Ross William , Dagher Ally , Martins Bruno Gomes Santos , Fernandes Juliana Campos Hasse 
Published: October 2024

Objective: The aim of this review was to identify newly discovered bacteria from individuals with periodontal/peri-implant diseases and organize them in new clusters (GF-MoR complexes) to update Socransky&rsquo;s complexes (1998). Methods: The focus question was developed based on the PCC (Population, Concept, Context) strategy: &ldquo;In patients with periodontal and/or peri-implant disease, what bacteria (microorganisms) were detected through laboratory assays?&rdquo; The search strategy was applied to PubMed/MEDLINE, PubMed Central, and Embase. The search keyterms, combined with Boolean markers, were: (1) bacteria, (2) microbiome, (3) microorganisms, (4) biofilm, (5) niche, (6) native bacteria, (7) gingivitis), (8) periodontitis, (9) peri-implant mucositis, and (10) peri-implantitis. The search was restricted to 1998&ndash;2024 and English language. The bacteria groups in the oral cavity obtained/found were retrieved and were included in the GF-MoR complexes which were based on the disease/condition, presenting six groups: (1) Health, (2) Gingivitis, (3) Peri-implant mucositis, (4) Periodontitis, (5) Peri-implantitis, and (6) Necrotizing and Molar-Incisor (M-O) pattern Periodontitis. The percentual found per group refers to the number of times a specific bacterium was found associated with a particular disease. Results: A total of 381 articles were found; 162 articles were eligible for full-text reading (k=0.92); 9 articles were excluded with justification, and 153 were included in this review (k=0.98). Most of the studies reported results for Health condition, Periodontitis, and Peri-implantitis (3 out of 6 GF-MoR clusters), limiting the number of bacteria found in the other groups. Therefore, it is essential to understand that bacterial colonization is a dynamic process, and the bacteria present in one group can also be present in other one or others, such as observed with the bacteria found in all groups (Porphyromonas gingivalis, Tannarela forsythia, Treponema denticola, and Aggregatibacter actinomycetemcomitans) (GF-MoR&rsquo;s red Triangle); the second most observed bacteria were grouped at GF-MoR&rsquo;s blue Triangle: Porphyromonas spp., Prevotela spp., and Treponema spp., present in 5 of the six groups; and the third most detected bacteria were clustered in the grey Polygon (GF-MoR&rsquo;s grey Polygon): Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens. These three geometric shapes had the most relevant bacteria for periodontal and peri-implant diseases. Specifically, per group, GF-MoR&rsquo;s Health had 58 species; GF-MoR&rsquo;s Gingivitis presented 16 bacteria; the GF-MoR&rsquo;s Peri-implant mucositis included 17 bacteria; GF-MoR&rsquo;s Periodontitis group had 101 different bacteria; GF-MoR&rsquo;s Peri-implantitis presented 61 bacteria; and the last group was a combination of Necrotizing diseases and Molar-Incisor (M-I) pattern Periodontitis, with seven bacteria. Observing the top seven bacteria of all groups, all were gram-negative; Groups 4 and 5 (Periodontitis and Peri-implantitis) presented the same top seven bacteria. Conclusion: For the first time in the literature, GF-MoR&rsquo;s complexes are presented, gathering the bacteria according to the condition found and including more bacteria than Socransky&rsquo;s complexes. On this understanding, this study can drive future research into treatment options for periodontal and peri-implant diseases, guiding future studies and collaborating to prevent and worsen systemic conditions. Moreover, it permits the debate about the evolution of the bacterial clusters correlated to periodontal and peri-implant diseases and conditions.