AimTo evaluate the prevalence of peri‐implant diseases and to identify risk/protective indicators of peri‐implantitis.Materials and MethodsTwo hundred and forty randomly selected patients from a university clinic database were invited to participate. Those who accepted, once data from their medical and dental history were collected, were examined clinically and radiographically to assess the prevalence of peri‐implant health and diseases. Peri‐implantitis was defined as the presence of BoP/SoP together with radiographic bone levels (BL) ≧2 mm. An intermediate peri‐implant health category between peri‐implant mucositis and peri‐implantitis was also identified, defined by the presence of BoP/SoP together with 1 mm ≦BL < 2 mm. A multilevel multivariate logistic regression analysis was carried out to identify those factors associated either positively (risk) or negatively (protective) with peri‐implantitis.ResultsNinety‐nine patients with a total of 458 dental implants were analyzed. The prevalences of pre‐periimplantitis and of peri‐implantitis were, respectively, 31.3% and 56.6% at patient‐level, while 31.7% and 27.9% at implant level. The following factors were identified as risk indicators for peri‐implantitis: smoking (OR = 3.59; 95% CI: 1.52–8.45), moderate/severe periodontitis (OR = 2.77; 95% CI: 1.20–6.36), <16 remaining teeth (OR = 2.23; 95% CI: 1.05–4.73), plaque (OR = 3.49; 95% CI: 1.13–10.75), implant malposition (too vestibular: OR = 2.85; 95% CI: 1.17–6.93), implant brand (Nobel vs. Straumann: OR = 4.41;95% CI: 1.76–11.09), restoration type (bridge vs. single crown: OR = 2.47; 95% CI: 1.19–5.12), and trauma as reason of tooth loss (vs. caries: OR = 6.51; 95% CI: 1.45–29.26). Conversely, the following factors were identified as protective indicators: interproximal flossing/brushing (OR = 0.27; 95% CI: 0.11–0.68), proton pump inhibitors (OR = 0.08; 95% CI: 0.01–0.90), and anticoagulants (OR = 0.08; 95% CI: 0.01–0.56).ConclusionsPeri‐implant diseases are highly prevalent among patients with dental implants in this university‐based population. Several factors were identified as risk‐ and protective‐ indicators of peri‐implantitis.