Abstract
INTRODUCTION: Peri-implantitis is an inflammatory condition involving soft tissue and bone loss around dental implants. Traditional diagnostic methods may miss early signs, leading to interest in using molecular markers for earlier and more accurate detection. This study investigated the roles of interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-α) in peri-implantitis by comparing their levels in peri-implant crevicular fluid (PICF) between healthy implants and peri-implantitis groups. Therefore, this study aimed to clarify the diagnostic potential of this method in periodontally healthy patients. MATERIALS AND METHODS: A prospective, cross-sectional study was conducted on 64 systemically healthy adults (aged 18-70 years), equally divided into Group 1 with healthy implant (probing depth <4 mm, no bleeding on probing, no marginal bone loss) and Group 2 with peri-implantitis (probing depth ≥4 mm, bleeding on probing, marginal bone loss ≥2 mm) groups. The exclusion criteria were smoking (>10 pack-years), recent antibiotic use, pregnancy, and immunosuppressive conditions. The groups were matched for age, sex, and implant characteristics (Straumann, Basel, Switzerland). Clinical assessments were performed using an UNC-15 periodontal probe (Hu-Friedy; Chicago, IL, USA). PICF was collected using periopaper strips (Oraflow Inc., Smithtown, NY, USA) and stored in Corning tubes (Corning Inc., Corning, NY, USA). Cytokine levels were quantified using human IL-6, IL-10, and TNF-α enzyme-linked immunosorbent assay (ELISA) kits (R&D Systems, Minneapolis, MN, USA) on a SpectraMax M5 reader (Molecular Devices, San Jose, CA, USA). The data were subjected to statistical analyses. RESULTS: The peri-implantitis group showed significantly higher plaque index (2.66 ± 0.40) and probing depth (4.85 ± 0.41 mm) compared to the healthy implant group (plaque index: 0.96 ± 0.27; probing depth: 3.09 ± 0.38 mm). Cytokine levels in PICF were markedly elevated in peri-implantitis cases: IL-6 (235.56 ± 56.34 pg/mL vs. 22.88 ± 8.06 pg/mL), IL-10 (73.13 ± 15.11 pg/mL vs. 13.13 ± 4.25 pg/mL), and TNF-α (148.94 ± 53.99 pg/mL vs. 8.31 ± 2.89 pg/mL). Logistic regression identified plaque index (OR = 162.37), probing depth (OR = 33.57), and smoking (OR = 20.50) as strong predictors of peri-implantitis, while longer loading time, male sex, and posterior implant location showed protective associations. CONCLUSION: IL-6, IL-10, and TNF-α levels were significantly elevated in patients with peri-implantitis, supporting their diagnostic potential. Plaque control and smoking cessation are critical for prevention, and biomechanical factors influence the risk.