DIAGNOSTICS, cilt.16, sa.7, 2026 (SCI-Expanded, Scopus)
Background: Obesity is associated with alterations in the immune response through increased systemic inflammation. This systemic inflammatory state may increase the risk of peri-implantitis, a condition characterized by infection and tissue destruction around dental implants. Therefore, this cross-sectional clinical study aimed to investigate the association between obesity and peri-implant health. Methods: In this observational clinical study, a total of 80 patients were evaluated, including a peri-implant healthy non-obese control group (CG) (n = 20), peri-implantitis non-obese group (PG) (n = 20), peri-implant healthy obese group (OG) (n = 20), and peri-implantitis obese group (POG) (n = 20). Peri-implant clinical measurements (plaque index [PI], gingival index [GI], bleeding on probing [BOP], and probing depth [PD]) were obtained from the participants. In addition, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and matrix metalloproteinase-8 (MMP-8) levels were measured in peri-implant crevicular fluid (PICF) samples. Results: PI, GI, BOP, and PD levels were significantly higher in the POG and PG than in the other groups (p < 0.05). PICF volume was found to be higher in the POG and PG than in the control group (p < 0.05). TNF-alpha levels increased significantly in all groups compared with the control group, and IL-1 beta levels were highest in the POG (p < 0.05). Conclusions: The findings of this cross-sectional study suggest a potential association between increased proinflammatory cytokine levels and altered peri-implant inflammatory responses in patients with obesity. Trial registration: This study was registered on ClinicalTrials.gov (Identifier: NCT07183163) on 18 September 2025 (retrospectively).