Clinical and microbiological findings in patients with peri-implantitis: A cross-sectional study

Objective: The aim of this study was to analyze clinical and microbiological characters in subjectsand implants affected and not affected by peri-implantitis. Additionally, same features wereanalyzed also intra-individually, comparing healthy and diseased implants within the same subject.Materials and methods: A total of 534 patients who received at least 1 implant and coming toroutine check-up or spontaneous visits at the University of Valencia were recruited. Clinicalparameters including Bleeding on probing (BoP), Probing pocket depth (PPD), and Pi werescreened. Samples for microbiological analysis were obtained from three locations: peri-implantsulci (PIS), inner parts of the implant connections (I), and gingival sulci of neighboring teeth (GS).Quantitative real-time PCR was performed for total counts of 10 microorganisms.Results: A total of 534 patients with 1507 dental implants were analyzed. The prevalence ofperi-implantitis was found 10.3% for patients and 7.3% for implants. Higher percentage of healthyperiodontal subjects were found in the non-peri-implantitis group. The analysis within the 53patients affected by peri-implantitis revealed that the implants affected by peri-implantitispresented a higher percentage of plaque, BoP, and number of implants presenting <2 mmattached gingiva. Additionally, more cemented crowns and implants inserted in bone-augmentedsites were found among the diseased implants. The microbiologic analysis presented no relevantdifferences between the analysis at the peri-implant sulcus (PIS) and the connections inside theabutments surfaces (PI). The microbial composition at the neighboring teeth (GS) resembled thecomposition found at the PIS with a high frequency of Pg, Tf, Pi, PM, and Ec.Conclusions: The results of this study seem to indicate that inadequate oral hygiene and thepresence of bleeding from the gingiva/mucosa in patients with dental implant were associatedwith an higher prevalence of peri-implantitis; moreover, in the patients affected by periimplantitis, the lack of sufficient height keratinized mucosa (<2 mm) and bone regenerativeprocedures at implant level were also associated to higher prevalence of peri-implantitis as well.