Inclusion Criteria:  Partially edentulous patients, rehabilitated with at least one dental implant in the maxilla or mandible; Presence of Peri-implantitis; No implant mobility; Treated periodontal disease; No systemic diseases that could influence the outcome of the therapy (i.e. uncontrolled diabetes, osteoporosis, bisphosphonate medication). Non-smoker or light smoking status in smokers (<10 cigarettes/day).  Exclusion Criteria:  (1) Pregnant, lactating women and non-collaborating patients will be excluded from the study.