Treatment procedure~After clinical parameters were recorded and samples were taken, all patients underwent a single episode of non-surgical therapy. It implied a mechanical method for debridement of implants and remaining dentition in order to reduce signs of inflammation. Instructions for oral hygiene were proposed in the same visit.~Peri-implantitis surgical treatment was conducted by one experienced surgeon two weeks after non-surgical therapy. After granulation tissue removal and mechanical implant surface cleaning with graphite curettes (Straumann Dental Implant System Straumann AG, Basel, Switzerland), decontamination of implant surface was conducted. In the study group, for the decontamination of implant surfaces and peri-implant tissues photodynamic therapy was performed (HELBO, Photodynamic Systems GmbH, Wels, Austria), while in the control group, after removal of granulation tissue, 1% gel of chlorhexidine (Chlorhexamed® - Direkt) was put on the implant surface. One minute after exposing the implant surface with CHX, it was irrigated for 1 min by saline. Bone augmentation and bio-resorbable membrane were applied in peri-implant defects using the bovine bone substitute and collagen membrane (Bio-Oss and Bio Gide, GeistlichPharma; Dembone). The mucoperiosteal flaps were repositioned and sutured [17, 19].~Patients were prescribed antibiotics (Amoxicillin, 500 mg, three per day, 5 days). It was recommended that patients don't use mouthwash during the postoperative period.~Clinical, immunological and microbiological parameters were measured and assessed baseline, three, six, 12 and 24 months postoperatively. Immunological parameters (IL-17, IL-1β, IL-6) were analysed by ELISA while microbiological samples were collected before the therapy, during the surgery, and at follow-up periods.~Assessment of implant macro- and micro- design were additionally assessed.
Photodynamic therapy (PDT) is suggested as an adjuvant treatment method to the surgery in peri-implantitis treatment. The primary goal of peri-implantitis therapy is the removal of the causative bacteria from the implant surface and surrounding tissues in order to improve the process of re-osseointegration and achieve long term implant stability. Accordingly, the aims of the study were to evaluate clinical, immunological and microbiological outcomes after surgical therapy of peri-implantitis following PDT.