Surgical Treatment of Peri-implantitis

The aim of this randomized controlled study is to evaluate the possible benefit of a regenerative treatment protocol (placing a bone substitute covered by a bioresorbable collagen membrane) compared to surgical treatment alone, for peri-implantitis therapy.

The hypothesis is that there will be a greater number of patients with successful treatment of peri-implantitis following the use of a bone substitute/collagen membrane compared to surgical peri-implantitis therapy without the bone substitute/collagen membrane.

The project will be conducted as a two-armed randomized controlled clinical trial of 1-year duration. Forty systemically healthy patients with ≥1 implant diagnosed with peri-implantitis requiring surgical therapy will be enrolled.

Baseline measurements will be performed after non-surgical therapy (removal supramucosal biofilm/calculus, oral hygiene instruction and correction of prosthetic factors) and treatment of periodontitis.

Baseline measurements will include probing depth, position of mucosal margin, presence of plaque, presence of bleeding and/or suppuration on probing, PROMs and radiographs. Measurements will be recorded at 4 sites per implant.

Following the baseline measurements participants will be randomly assigned to either Control Group (Group 1): access flap and implant cleaning or Test Group (Group 2): access flap, implant cleaning and addition of a bone substitute material covered by a collagen membrane.

Participants in both treatment groups will be prescribed systemic antimicrobials (Amoxicillin 500 mg tds and Metronidazole 400 mg tds) for 7 days starting from the day of surgery.

In addition an antibacterial mouthrinse (chlorhexidine digluconate 0.2%) will be prescribed for a period of 4 weeks following surgery.

Participants will be asked to attend follow-up visits for review of healing (week 1 and 4) and maintenance care (3, 6, 9, and 12 months).

Clinical examinations will be performed by a calibrated blinded examiner at baseline and 12 months after therapy. Clinical measurements will be taken using a periodontal probe at 4 sites per implant to record presence of plaque, bleeding, probing depth and recession of the soft tissue.

PROMS will be assessed at 1 week, 4 weeks and at 12 months. Radiographic assessments Intra-oral radiographs and cone beam CT scan will be obtained prior to surgery and at 12 months. Oral-maxillofacial radiologists will. perform the radiographic analysis and will be blinded to the treatment procedure.

Primary outcome variables include (1) resolution of peri-implantitis (probing depth reduction and absence of BoP, suppuration) (2) recurrence of disease (BoP, suppuration and increase in PPD and progression of bone loss.

Inclusion criteria

Presence of ≥ 1 implant with a probing depth (PD) ≥ 5 mm with bleeding and/or suppuration (SUP) on probing, and peri-implant bone loss ≥ 3mm with an intraosseous defect component

Exclusion criteria

• Smokers > 10 cigarettes per day
• Patients with uncontrolled diabetes mellitus
• Pregnant or lactating women (self reported)
• Patients with a systemic illness that preclude them from oral surgery
• Patients with an allergy to amoxicillin or metronidazole or chlorhexidine.
• Patients requiring antibiotic prophylaxis and Patients who have taken antibiotics in the past 3 months