Surgical Treatment of Peri-implantitis With and Without an Initial Non-surgical Approach

Inclusion Criteria: Any patient having at least one implant affected by severe peri-implantitis, being at least 18 years old and able to sign an informed consent form will be potentially eligible for this trial. Severe peri-implantitis will be defined as peri-implant probing pocket depth \[PPD\] ≥6 mm in at least 1 site of the implant, together with bleeding and/or suppuration on probing \[BoP and/or SoP, respectively\] and radiographically documented marginal bone loss/level ≥3 mm (Carcuac et al. 2016) on implants in function by at least 1 year. In case of absence of baseline radiographs, the reference point for baseline bone levels will be considered where bone was likely to be at implant placement. Exclusion Criteria: Patients fitting to all the inclusion criteria as above will be not included in the study if they appear to be unable to attend to the study-related procedures (including the follow-up visits) or if one or more of the following systemic or local exclusion criteria are found in the enrolment phase. Systemic primary exclusion criteria: * compromised general health which contraindicates the study procedures (ASA IV-VI patients); * systemic diseases which could influence the outcome of the therapy (uncontrolled diabetes mellitus); * pregnant or nursing women; * chronic use of corticosteroids or NSAID or immune-modulator drugs (any type and any dose); * patients who need use of medications affecting bone metabolism or peri-implant mucosa (bisphosphonates, any type and any dose). Local primary exclusion criteria: * history of peri-implantitis treatment on implants to be included in the study (included topical antibiotics); * hopeless implants (e.g. mobility) to be included in the study. Secondary exclusion criteria: \- uncompliant patients (poor oral hygiene 2 weeks after OHI).