Influence of Metabolic Syndrome on Peri-Implant Tissue Health and Disease: A Comparative Evaluation of Clinical, Radiographic, and Red Complex Microbiological Parameters.

Metabolic syndrome (MetS) is a systemic human health condition characterized by obesity, hypertension, dyslipidemia, and insulin resistance, all of which may compromise peri-implant tissue health and contribute to peri-implant disease. This study aimed to evaluate the influence of MetS on peri-implant clinical, radiographic, and microbiological parameters one year after functional implant loading, with relevance to public health and implant-related wellbeing. This case-control study was conducted at the Department of Implantology, Saveetha Dental College, Chennai, India, from March to December 2024. Ninety-eight systemically screened, periodontally healthy adults (35-65 years) with functional dental implants were enrolled and divided into MetS (n = 49) and non-MetS groups (n = 49) based on NCEP ATP III criteria. Clinical parameters [Plaque Index (PI), Gingival Index (GI), probing pocket depth (PPD), and clinical attachment level (CAL)], radiographic crestal bone level (CBL), and the prevalence of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola (via PCR analysis) were assessed. Statistical analyses were performed using independent t-test and Chi-square test (P < 0.05). MetS patients exhibited significantly higher PI (2.4 ± 0.3), GI (2.5 ± 0.2), PPD (6.5 ± 1.3 mm), CAL (7.2 ± 1.2 mm), and CBL loss (2.6 ± 0.4 mm) than non-MetS participants (all P = 0.00). Microbiological analysis revealed higher detection of P. gingivalis (59.2% vs. 10.2%), T. denticola (28.6% vs. 2.0%), and T. forsythia (22.4% vs. 4.1%) among MetS cases, with significant group differences (P ≤ 0.01). MetS is associated with greater peri-implant plaque accumulation, inflammation, bone loss, and colonization by red complex pathogens, underscoring its potential role as a risk indicator for peri-implantitis.