Collagen Membrane and Allograft in Peri-Implantitis Surgery

Peri-implantitis is a plaque-associated pathological condition characterized by inflammation of the peri-implant mucosa and progressive loss of supporting bone around dental implants. Due to the structural differences between periodontal and peri-implant tissues, peri-implantitis lesions often show rapid progression and may require surgical intervention in advanced cases. Surgical therapy aims to eliminate the inflammatory lesion, decontaminate the implant surface, and manage peri-implant bone defects.

Regenerative surgical approaches have been proposed to reconstruct peri-implant bone defects and improve treatment outcomes. Bone graft materials are commonly used to provide an osteoconductive scaffold and promote new bone formation. In addition, barrier membranes may be used to stabilize the grafted area and prevent the migration of epithelial and connective tissue cells into the defect site. Resorbable collagen membranes are widely used because of their biocompatibility, resorbability, and ability to support wound stabilization during the healing process.

However, the adjunctive benefit of using a collagen membrane together with a bone graft in the surgical treatment of peri-implantitis remains controversial. Furthermore, limited data are available regarding the biological response associated with these regenerative procedures.

The present randomized clinical trial aims to evaluate the adjunctive effect of a resorbable collagen membrane used in combination with an allograft in the surgical treatment of peri-implantitis. A total of 44 patients diagnosed with peri-implantitis associated with circumferential intrabony defects are randomly assigned to one of two treatment groups: (1) allograft combined with a resorbable collagen membrane (test group) and (2) allograft alone (control group).

Clinical parameters including probing depth, bleeding on probing, and suppuration are recorded at baseline and during follow-up examinations. Radiographic marginal bone levels are evaluated using standardized periapical radiographs. In addition, peri-implant crevicular fluid samples are collected at baseline, 1 month, and 3 months to determine platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) levels using ELISA. These biochemical markers are analyzed to evaluate the biological healing response following surgical treatment.

The outcomes of the two treatment approaches are compared in terms of clinical, radiographic, and biochemical parameters in order to determine whether the use of a collagen membrane provides additional benefit in the reconstructive surgical treatment of peri-implantitis.

Inclusion criteria

• Patients diagnosed with peri-implantitis characterized by bleeding and/or suppuration on probing and increased probing depth around dental implants.
• Presence of circumferential intrabony peri-implant defects requiring reconstructive surgical treatment.
• Patients aged 18 years or older.
• Presence of functioning dental implants in the oral cavity.
• Patients who are able and willing to attend follow-up visits and provide informed consent.

Exclusion criteria

• Patients with uncontrolled systemic diseases that could affect wound healing.
• Use of antibiotics or anti-inflammatory drugs within the last 3 months.
• Pregnancy or lactation.
• Heavy smoking habits.
• Poor oral hygiene or lack of compliance with periodontal maintenance therapy.
• Previous surgical treatment for peri-implantitis at the study site.