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 reconstructive approach (xenograft bone graft granules and collagen membrane, BioOss and BioGide, Geistlich, Wolhusen). The test group will be the same with the exception of an autologous sub-epithelial connective tissue palatal graft, sutured beneath the flap, which will be used in addition to grafting materials.

Outcomes will include CAL, PD, MR, defect resolution, PI, BoP, SUPP, patient-reported outcome measures including an aesthetic self-evaluation.

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 reservable 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 CAL, clinical attachment level (primary outcome), PD or probing depth, MR or mucosal recession, defect resolution (composite outcome made up of simultaneous absence of PD\>5 mm, BOP/SUP and bone level changes \>0.5 mm, PI, BoP or bleeding upon probing, suppuration SUP on probing, SUP on palpation, patient-reported outcome measures including an aesthetic self-evaluation.

The measures will be recorded at baseline, 6-, 12-, 18- and 24 months. Radiographic bone levels will be compared with 2 week image at 12 and 24 months

Eligibility Criteria:
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.