Peri-implantitis treatment with an open barrier double membrane technique (collagen + dense polytetrafluoroethylene).

Abstract

Background: Reconstructive treatments of peri-implantitis are carried out with the principles of guided bone regeneration, with a non-submerged or with a submerged approach. The authors describe a new technique for the reconstruction of intra-bony vertical defects caused by peri-implantitis, which requires the removal of the prosthetic superstructure to have better access to the surgical site, in order to perform the defect debridement and the implant surface decontamination and detoxification, before placing the reconstructive biomaterials.

Methods: A 2 mm high cap screw was connected to the implant with the aim of not letting a cross-linked collagen membrane to collapse over the implant threads. This membrane covered the implant and the whole defect, filled with a porcine bone graft wet with hyaluronic acid. A second membrane, made of dense polytetrafluoroethylene (dPTFE), was placed over the previous one and left exposed, avoiding a second intervention for its removal, which occurred after a 5-week healing time by grasping the membrane with forceps and removing it with a gentle tug. After cap screw removal, it was possible to insert an healing abutment.

Results: The augmented bone remained stable 2.5 years after prosthetic superstructure re-insertion. Soft tissue architecture was maintained since the flaps were not repositioned coronally, the mucogingival line and the fornix were not distorted, and there was no reduction of keratinized mucosa.

Conclusions: The benefits of this technique include the reliable defect isolation and containment of graft particles, ease of membrane placement, simplified dPTFE membrane removal, and preservation of mucogingival architecture.

Key points: The prosthetic superstructure removal provides better access to the surgical site in order to perform the defect debridement and the implant surface decontamination and detoxification, before placing the reconstructive biomaterials. The use of a 2 mm high closure cap or a short healing abutment prevents membrane collapse on the implant threads. Since the dense polytetrafluoroethylene membrane is not buried, but intentionally left exposed, its removal after a 5-6-week healing period doesn't require a second surgery. Furthermore, it is also possible to re-insert the prosthetic superstructure, reducing the overall treatment time generally respected with the conventional submerged approach, which involves uncovering the implant after a healing period of 6-9 months.

Plain language summary: The authors describe a new technique for the reconstruction of intra-bony vertical defects caused by peri-implantitis, which requires the removal of the prosthetic superstructure to have better access to the surgical site, in order to perform the defect debridement and the implant surface decontamination and detoxification, before placing the reconstructive biomaterials. Two membranes are used: a collagen membrane that covers the whole defect filled with a xenograft, and a dense polytetrafluoroethylene membrane, applied over the collagen one, that is intentionally left exposed in order to easily remove it after a 5-6-week healing period without a second surgery. This cost-effective, predictable treatment protocol is indicated for the general practitioner who usually doesn't treat complex cases requiring advanced skills.