Peri-implantitis Management: Surgical and Maintenance Outcomes

Inclusion Criteria To be enrolled, the participant must met the following inclusion criteria: 1. Aged 18 or older. 2. In good general health, classified as ASA Physical Status I or II. 3. Diagnosed with peri-implantitis requiring resective surgical treatment, characterized by: Bleeding on probing (BOP) around dental implants. Probing pocket depths (PPD) greater than 6 mm. Implants in function for over 1 year with progressive bone loss exceeding 3 mm. Initial screening confirmed by panoramic radiographs, cone-beam computed tomography (CBCT), and clinical diagnosis. To be enrolled in the maintenance phase, participants must meet clinical stability criteria at the time of enrollment: * Probing depth (PD) ≤ 5 mm * Bleeding on probing (BOP) ≤ 1 point * Absence of suppuration (SOP) * Absence of progressive bone loss compared to pre-treatment bone levels Exclusion Criteria: 1. Patients with autoimmune or systemic inflammatory diseases (e.g., lupus, rheumatoid arthritis) that could alter immune cell profiles independent of local peri-implant inflammation. 2. Chronic use of systemic corticosteroids or immunosuppressants within the past 3 months. 3. Uncontrolled diabetes (HbA1c \> 7.5%) due to its potential impact on healing and immune response. 4. Active infection or antibiotic use in the 30 days prior to baseline sampling. 5. Pregnancy or breastfeeding. 6. Inability to undergo venipuncture or tolerate soft tissue biopsy. 7. Inability to attend the 3-month follow-up visit or comply with study protocol. 8. History of malignancy requiring systemic therapy within the past 5 years.