MICRO-SURG: Subgingival Microbiome in Peri-Implantitis, Regenerative, and Resective Periodontal Surgery

MICRO-SURG: Investigation of Subgingival Microbiome Changes Following Surgical Peri-Implantitis Therapy, Regenerative Periodontal Surgery, and Resective Periodontal Surgery Using Next-Generation Sequencing

This clinical study investigates how the subgingival microbiome changes after three different periodontal and peri-implant surgical procedures: (1) resective periodontal surgery, (2) regenerative periodontal surgery, and (3) peri-implantitis surgery. The aim is to characterize microbial shifts associated with these commonly used surgical treatments and to determine whether the type of surgery influences the recovery or disruption of the subgingival ecosystem. Adult patients with periodontitis or peri-implantitis will receive the procedure indicated for their condition. Subgingival plaque samples will be collected at baseline and at defined postoperative follow-up intervals. Microbiome analysis will be performed using next-generation sequencing (NGS), and microbial changes will be evaluated with the Subgingival Microbial Dysbiosis Index (SMDI). Insights from this study may help improve prevention, diagnostics, and treatment strategies for periodontal and peri-implant diseases.

Inclusion Criteria:

• Age 18 years or older
• Confirmed diagnosis of Peri-implantitis (for the peri-implantitis surgery arm), or Stage III/IV periodontitis (for the periodontal surgery arms)
• Indication for surgical therapy corresponding to the assigned study arm
• Ability to understand the study procedures and provide written informed consent
• Adequate oral hygiene (API/SBI according to the clinician's judgment)
• Willingness and ability to attend all follow-up visits
• Willingness to provide salivary and subgingival plaque samples for microbiome analyses (NGS, SMDI)

Exclusion Criteria:

• Systemic conditions contraindicating oral surgical procedures
• Severe systemic diseases (e.g., uncontrolled diabetes mellitus, immunosuppressive disorders)
• Use of systemic antibiotics within the previous 3 months
• Active COVID-19 infection at the time of surgery
• Pregnancy or breastfeeding
• Drug or alcohol abuse
• Smoking more than 10 cigarettes per day
• Known allergies to materials used in the assigned intervention (e.g., local anesthetics, sutures, membranes, bone grafting materials)
• Participation in another clinical study within the previous 30 days
• Acute oral infections that contraindicate participation
• Inability or unwillingness to comply with all follow-up appointments Lack of capacity to provide informed consent