To take part in this study, patients must present at least one implant diagnosed with peri-implantitis [i.e., peri-implant bone level ≥ 3mm apical to the most coronal portion of the intraosseous part of the implant, peri-implant pocket depth (PPD) ≥ 6 mm, and presence of bleeding and/or suppuration on gentle probing (BOP/SOP) (Berglunh et al. 2018)  Inclusion Criteria:  Men and women over 18 years old. Presence of ≥ 1 endosseous implants with clinical and radiographic signs of peri- implantitis [i.e., peri-implant bone level ≥ 3mm apical to the most coronal portion of the intraosseous part of the implant, PPD ≥ 6 mm, and presence of bleeding and/or suppuration on gentle probing (BOP/SOP). Implant function time ≥ 1 year. Vertical peri-implant bone defect (defects of 2-3 walls and a defect depth ≥ 3 mm). Presence of at least 2 mm of keratinized mucosa. Absence of active periodontal disease. Good level of oral hygiene (Plaque Index < 25%) (O'Leary et al. 1972) Screw-retained single-unit crowns and partial dental prosthesis that allowed correct access for brushing; and, if not, Prostheses that could be modified. Absence of occlusal overload.  Exclusion Criteria:  Clinical implant mobility. Radiographic peri-implant bone loss > 50%. Pregnancy or lactating females. Any medical condition which contraindicated surgical peri-implant therapy. Previous non-surgical treatment (i.e., subgingival debridement) of the affected implants at least 12 months before. Previous surgical treatment of the affected implants. Systemic diseases, medications, or conditions that may compromise wound healing influencing the outcome of the therapy. Known allergy or intolerance to metronidazole or ibuprofeno. Use of systemic antibiotics during the previous 3 months. Use of systemic antibiotics for endocarditis prophylaxis. Smoking more than 10 cigarettes/day.