Due to the world-wide increase in treatments involving implant placement, the incidence of peri-implant disease is increasing. Late implant failure is the result of the inability to maintain osseointegration, whose most important cause is peri-implantitis. The aim of this study was to analyze the clinical, microbiological, and immunological aspects in the peri-implant sulcus fluid (PISF) of patients with healthy dental implants and patients with peri-implantitis. PISF samples were obtained from 24 peri-implantitis sites and 54 healthy peri-implant sites in this prospective cross-sectional study. The clinical parameters recorded were: modified gingival index (mGI), modified plaque index (mPI) and probing pocket depth (PPD). The periodontopathogenic bacteria Tannerella forsythia, Treponema denticola and Porphyromonas gingivalis were evaluated, together with the total bacterial load (TBL). PISF samples were analyzed for the quantification of Interleukin (IL)-8, IL-1β, IL-6, IL-10 and Tumor Necrosis Factor (TNF)-α using flow cytometry (FACS). The mGI and PPD scores in the peri-implantitis group were significantly higher than the healthy group (p < 0.001). A total of 61.5% of the patients with peri-implantitis had both arches rehabilitated, compared with 22.7% of patients with healthy peri-implant tissues; there was no implant with peri-implantitis in cases that received mandibular treatment exclusively (p < 0.05). Concentrations of Porphyromonas gingivalis (p < 0.01), association with bacteria Porphyromonas gingivalis and Treponema denticola (p < 0.05), as well as the TBL (p < 0.05) are significantly higher in the peri-implantitis group. IL-1β (p < 0.01), IL-6 (p < 0.01), IL-10 (p < 0.05) and TNF-α (p < 0.01) are significantly higher at the sites with peri-implantitis compared to healthy peri-implant tissue, while IL-8 did not increase significantly. The results of the present study involving a limited patient sample suggest that the peri-implant microbiota and which dental arch was rehabilitated involved could contribute to bone loss in peri-implantitis. A significant relationship is observed between the concentration of cytokines (interleukins 1β, 6 and 10 and TNF-α) and the inflammatory response in peri-implantitis tissue.

Peri-implantitis is a late complication of dental implant treatment, induced by microbiological changes. Since the disorder is frequent, a review is indicated of the microorganisms that influence it and of the existing treatment options. To conduct a literature review of the microbiota associated to peri-implantitis and the existing treatment options. A PubMed literature search was made of the studies on the microbiota associated to dental implants in healthy patients and patients with peri-implantitis, as well as of the latest treatment developments, using the following key words: "peri-implantitis AND microbiota", "periimplantitis AND microbiota", "peri-implantitis AND treatment", and "periimplantitis AND treatment". Only clinical studies in humans were considered. The following criteria were applied for including articles in the analysis: a) for the peri-implant microbiota, the search limits were human studies after the year 2000; and b) for the treatment of peri-implantitis, the search limits were randomized and controlled clinical trials (RCTs) in humans, with a minimum follow-up of 4 months, and publication after the year 2000. A total of 18 articles were selected in relation to peri-implant microbiota, and 13 in relation to the treatment of peri-implantitis (8 involving nonsurgical mechanical treatments and 5 surgical procedures). Evaluation of the literature has shown the microbiota associated to peri-implantitis to be more complex than that found under healthy peri-implant conditions - the main flora consisting of anaerobic gramnegative bacteria. No clear criteria have been identified for the diagnosis and treatment of peri-implantitis.