Treatment of Peri-implantitis With or Without Simultaneous Soft Tissue Augmentation

The study will aim to compare two modalities in the reconstructive treatment of peri-implantitis defects.

More specifically, the control group will be a "pure" reconstructive approach (xenograft bone graft granules and resorbable collagen membrane, BioOss and BioGide, Geistlich, Wolhusen). This is in accordance with gold standard practices of reconstructive therapy of peri-implant defects.

The test group will be treated with the same approach and materials, with the exception of an autologous sub-epithelial connective tissue palatal graft, sutured beneath the flap, which will be used in addition to the grafting materials. The graft will be harvested from the homolateral palate (molar region).

Outcomes will include clinical attachment level (CAL; primary outcome), probing depth (PD), mucosal recession (MR), defect resolution (a composite outcome defined as the simultaneous absence of PD > 5 mm, bleeding on probing [BOP] and/or suppuration [SUP], and bone level changes > 0.5 mm), plaque index (PI), BOP, suppuration on probing, suppuration on palpation, surgical duration, the Early Wound Healing Index (EHI), and patient-reported outcome measures (PROMs), including aesthetic self-evaluation.

PROMs will assess patients' perception of surgery, pain intensity, perceived swelling, perceived bleeding, and analgesic intake.

Clinical measurements will be recorded at baseline and at 6, 12, 18, and 24 months. EHI will be assessed at 1 and 2 weeks postoperatively. Radiographic bone levels at 12 and 24 months will be compared with those recorded on radiographs obtained at baseline. All PROMs variables, as well as aesthetic self-evaluation, will be collected using specially designed questionnaires completed by the patients. PROMs data will be recorded at 4, 8, and 12 hours after surgery on the day of surgery (day 0), and daily from postoperative day 2 to day 7. Aesthetic self-evaluation will be recorded at baseline and at 6, 12, and 24 months postoperatively.

Inclusion criteria

• · Be able and willing to provide consent and sign the informed consent form.

• Be able and willing to comply with study procedures and follow-up appointments required by the study protocol.
• Age>18 years
• Presence of at least one implant affected with peri-implantitis, defined as the following con-dition: at least one site presenting peri-implant probing depth (PPD) >6 mm and simultane-ous presence of profuse BoP/SUP and a radiographically documented change in bone level greater than initial bone remodeling. In the likely event that a baseline radiographic image is absent, the bone level will be compared to where it would likely have been at the time of implant insertion and a difference of >3 mm from that level will be considered.
• Implants in function (i.e. loaded) for at least 1 year.
• Screw- and cement-retained suprastructures for both fixed and removable prostheses.

Exclusion criteria

• Compromised systemic health which contraindicates the study procedures.
• Pregnant or nursing women.
• Cigarette smoking>5 per day
• Systemic conditions compromising healing (i.e. diabetes mellitus). Patients with diabe-tes mellitus types I or II will be asked to provide information regarding their most re-cent HbA1c values. Only patients with HbA1c<7% will be enrolled.
• Patients taking medications known to interfere with gingival or bone metabolism.